K Number
K123355
Device Name
AMPLIVUE C. DIFFICILE ASSAY
Manufacturer
Date Cleared
2012-12-13

(43 days)

Product Code
Regulation Number
866.3130
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP Authorized
Intended Use
The AmpliVue™ C. difficile Assay is an in vitro diagnostic test for the direct, qualitative detection of the Clostridium difficile Toxin A gene (tcdA) in unformed stool specimens of patients suspected of having Clostridium difficile-associated disease (CDAD). The AmpliVue™ C. difficile Assay is intended for use as an aid in diagnosis of CDAD. The assay utilizes helicase-dependent amplification (HDA) for the amplification of a highly conserved fragment of the Toxin A gene sequence and a self-contained disposable amplicon device that allows for manual evaluation of assay results.
Device Description
The AmpliVue™ C. difficile Assay combines simple specimen processing, an isothermal amplification technology named helicase-dependent amplification (HDA), and a self- contained disposable amplicon detection device for the detection of Clostridium difficile directly from CDAD-suspected stool specimens. A swab is used to transfer a small amount of specimen into a dilution tube. The diluted sample is then transferred into a sample lysis buffer tube, and the cells are lysed by simple heat treatment. After heat treatment, an aliquot of the lysed sample is added to a reaction tube containing a lyophilized mix of HDA reagents, including primers specific for the amplification of a fragment from the conserved 5' end of the tcdA gene that are located within the PaLoc of toxigenic C. difficile strains. The assay also includes a process control to monitor specimen processing and to confirm the integrity of the assay reagents and cassette detection, as well as to assess for HDA-inhibitors that may be present within the stool specimen. Competitive amplification of the process control DNA also takes place unless inhibitory substances are present or the specimen processing fails. The HDA reaction is asymmetric so that an excess of single stranded DNA is formed from a biotinylated primer present within the reaction mix. The capture probes for each amplicon bind to the corresponding biotinylated single-stranded DNA forming dual labeled amplicons. After completion of the HDA reaction, the reaction tube is transferred to a single-use, disposable cassette for detection. The self-contained cassette is comprised of two individual components: an amplicon cartridge that holds the running buffer and the single 0.2-ml thin wall reaction tube containing the amplified product. The detection chamber houses the amplicon cartridge and a vertical-flow DNA detection strip embedded into the cassette. The DNA detection strip is coated with an anti-FITC antibody and an anti-DNP antibody that serve as the C. difficile test (T2) line and the control (C) line in the assay, respectively. A razor blade and a plastic pin located at the bottom of the detection chamber opens the HDA reaction tube and the running buffer bulb when the handle of the detection chamber is closed. The mixture flows through a fiberglass paper connected to the DNA detection strip that contains a fiberglass pad pre-loaded with streptavidin-conjugated color particles for color visualization. The dual-labeled probe-amplicon hybrid is then detected by the lateral flow strip within the cassette. The bottom line captures the FITC-labeled probe-amplicon and the top line captures the DNPlabeled probe-amplicon. The biotin label attracts the streptavidin-conjugated color particles for visualization and the test result is shown as colored lines visible to the naked eye. Detection of C. difficile DNA is reported when the T2 and C lines are visible through the detection window of the cassette. No detection of C. difficile DNA is reported when only the C line is displayed. The assay is regarded as unresolved when neither line is displayed. The whole procedure takes approximately 75 minutes (Note: The T1 line present on the self-contained cassette is for a triplex assay and is not applicable/used for the AmpliVue C. difficile Assay).
More Information

Great Basin Scientific Portrait Toxigenic C. Difficile Assay - K113358

No
The device description details a manual, visual detection method based on lateral flow immunoassay technology, with no mention of automated analysis, algorithms, or learning processes.

No
This device is an in vitro diagnostic test designed to detect the Clostridium difficile Toxin A gene, aiding in the diagnosis of CDAD. It does not provide therapy or treatment for the disease.

Yes

The "Intended Use / Indications for Use" section explicitly states that the AmpliVue™ C. difficile Assay is "an in vitro diagnostic test" and "is intended for use as an aid in diagnosis of CDAD."

No

The device description clearly outlines physical components including tubes, a cassette, a detection strip, and reagents, indicating it is a hardware-based in vitro diagnostic test.

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

  • Intended Use: The "Intended Use / Indications for Use" section explicitly states that the AmpliVue™ C. difficile Assay is an "in vitro diagnostic test".
  • Purpose: The assay is designed to detect the Clostridium difficile Toxin A gene in unformed stool specimens to aid in the diagnosis of CDAD. This is a classic function of an in vitro diagnostic device, which is used to examine specimens from the human body to provide information for diagnosis, treatment, or prevention of disease.
  • Methodology: The device utilizes laboratory techniques (helicase-dependent amplification and a self-contained disposable amplicon device) to analyze a biological sample (stool).

The entire description aligns with the definition and purpose of an in vitro diagnostic device.

N/A

Intended Use / Indications for Use

The AmpliVue™ C. difficile Assay is an in vitro diagnostic test for the direct, qualitative detection of the Clostridium difficile Toxin A gene (tcdA) in unformed stool specimens of patients suspected of having Clostridium difficile-associated disease (CDAD). The AmpliVue™ C. difficile Assay is intended for use as an aid in diagnosis of CDAD. The assay utilizes helicase-dependent amplification (HDA) for the amplification of a highly conserved fragment of the Toxin A gene sequence and a self-contained disposable amplicon device that allows for manual evaluation of assay results.

Product codes

OZN

Device Description

` The AmpliVue™ C. difficile Assay combines simple specimen processing, an isothermal amplification technology named helicase-dependent amplification (HDA), and a self- contained disposable amplicon detection device for the detection of Clostridium difficile directly from CDAD-suspected stool specimens.
A swab is used to transfer a small amount of specimen into a dilution tube. The diluted sample is then transferred into a sample lysis buffer tube, and the cells are lysed by simple heat treatment. After heat treatment, an aliquot of the lysed sample is added to a reaction tube containing a lyophilized mix of HDA reagents, including primers specific for the amplification of a fragment from the conserved 5' end of the tcdA gene that are located within the PaLoc of toxigenic C. difficile strains. The assay also includes a process control to monitor specimen processing and to confirm the integrity of the assay reagents and cassette detection, as well as to assess for HDA-inhibitors that may be present within the stool specimen. Competitive amplification of the process control DNA also takes place unless inhibitory substances are present or the specimen processing fails. The HDA reaction is asymmetric so that an excess of single stranded DNA is formed from a biotinylated primer present within the reaction mix. The capture probes for each amplicon bind to the corresponding biotinylated single-stranded DNA forming dual labeled amplicons.

After completion of the HDA reaction, the reaction tube is transferred to a single-use, disposable cassette for detection. The self-contained cassette is comprised of two individual components: an amplicon cartridge that holds the running buffer and the single 0.2-ml thin wall reaction tube containing the amplified product. The detection chamber houses the amplicon cartridge and a vertical-flow DNA detection strip embedded into the cassette. The DNA detection strip is coated with an anti-FITC antibody and an anti-DNP antibody that serve as the C. difficile test (T2) line and the control (C) line in the assay, respectively. A razor blade and a plastic pin located at the bottom of the detection chamber opens the HDA reaction tube and the running buffer bulb when the handle of the detection chamber is closed.

The mixture flows through a fiberglass paper connected to the DNA detection strip that contains a fiberglass pad pre-loaded with streptavidin-conjugated color particles for color visualization. The dual-labeled probe-amplicon hybrid is then detected by the lateral flow strip within the cassette. The bottom line captures the FITC-labeled probe-amplicon and the top line captures the DNPlabeled probe-amplicon. The biotin label attracts the streptavidin-conjugated color particles for visualization and the test result is shown as colored lines visible to the naked eye. Detection of C. difficile DNA is reported when the T2 and C lines are visible through the detection window of the cassette. No detection of C. difficile DNA is reported when only the C line is displayed. The assay is regarded as unresolved when neither line is displayed. The whole procedure takes approximately 75 minutes (Note: The T1 line present on the self-contained cassette is for a triplex assay and is not applicable/used for the AmpliVue C. difficile Assay).

The Quidel AmpliVue C. difficile Assay contains sufficient reagents to process 16 specimens or quality control samples. The kit contains the following:
Detection Cassettes: Each cassette comes preloaded with all required probes and signal amplification solutions necessary to generate a test result. Quantity: 16/kit. Storage: 2° to 30°C
Dilution Buffer: Ready for use. Quantity: 16 tubes/kit 1.8 mL. Storage: 2° to 8°C
Lysis Buffer: Ready for use. Quantity: 16 tubes/kit 1 mL. Storage: 2° to 8°C
Reaction Tubes: Ready for use. Quantity: 16 tubes/kit. Storage: 2° to 8°C
Amplicon Cartridge: Each cartridge comes preloaded with all solutions required amplification. Quantity: 16/kit. Storage: 2° to 30°C
Flocked Swabs: Ready for use. Quantity: 16 swabs/kit. Storage: 2° to 30°C

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

Not Found

Anatomical Site

Not Found

Indicated Patient Age Range

Not Found

Intended User / Care Setting

For prescription use only.

Description of the training set, sample size, data source, and annotation protocol

Not Found

Description of the test set, sample size, data source, and annotation protocol

Not Found

Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

Precision/Reproducibility: For the Precision/Within Laboratory Repeatability study, a blinded four-member panel consisting of C. difficile positive and negative sample was tested by two operators, twice a day using a single assay lot of AmpliVue C. difficile Assay for thirteen (13) days. Overall Percent Agreement for C. difficile High Negative was 0% (0/48), for C. difficile Low Positive was 100% (48/48), for C. difficile Moderate Positive was 100% (48/48), for Negative was 100% (48/48), for C. difficile Positive Control was 100% (48/48), and for Assay Negative Control was 100% (48/48).
Reproducibility: A blinded and randomized study panel containing Clostridium difficile negative and positive samples were tested at three (3) test sites, two of which were clinical sites. Each site tested a reproducibility panel and assay controls for five (5) days in triplicate. The testing was done by two operators at each site. Each operator ran the panel once a day using one lot of AmpliVue™ C. difficile Assay. Overall Percent Agreement for C. difficile High Negative was 80% (72/90), for C. difficile Low Positive was 100% (89/89), for C. difficile Moderate Positive was 100% (90/90), for Negative was 100% (90/90), for C. difficile Positive Control was 100% (90/90), and for Assay Negative Control was 100% (90/90). One (1) sample was invalid.
Detection limit (LoD): The analytical sensitivity (LoD) of the Quidel AmpliVue C. difficile Assay was determined using quantified (CFU/mL) cultures of two C. difficile strains (ATCC 43255 {toxinotype 0} and CCUG 8864 {toxinotype X}) serially diluted in a negative fecal matrix. LoDs were 4.2 CFU/Assay for ATCC 43255 and 0.7 CFU/Assay for CCUG 8864. The final assay LoD is defined as the higher of the two strain concentrations where 95% positivity was observed, which is 4.2 CFU/assay.
Analytical Reactivity (Inclusivity): Twenty-four toxigenic strains for C. difficile were tested at 2 to 3x LoD in negative specimen matrix using three (3) AmpliVue C. difficile assay lots. The assay demonstrated detection of a broad range of toxigenic Clostridium difficile strains.
Cross Reactivity: The assay was evaluated by testing a panel of sixty-six (66) bacterial, viral and yeast microorganisms and human DNA, and in silico analysis for C. botulinum. The results demonstrate that the AmpliVue C. difficile Assay does not cross react with medically relevant levels of viruses or bacteria found in stool specimens.
Interfering Substances: Two toxigenic strains of C. difficile (ATCC 43255, toxinotype 0; CCUG 8864, toxinotype X) were evaluated against a test panel of thirty-four substances found in stool specimens. None of the substances tested were found to interfere with the AmpliVue C. difficile Assay.
Method comparison with predicate device: The performance of the AmpliVue C. difficile Assay was evaluated at four geographically diverse locations within the United States between January 2012 and October 2012. Eight hundred and forty (840) samples were tested by both the AmpliVue C. difficile Assay and the Tissue Culture Cytotoxicity Assay. One specimen (0.1%) was indeterminate in the cytotoxin assay. Four specimens (0.5%) were invalid in the AmpliVue C. difficile Assay when initially tested, with three yielding valid negative results on retest. One remained invalid. Analyses were based on initial results for 835 specimens.

Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)

Sensitivity: 93.6% (95% CI: 87.3% - 96.9%)
Specificity: 94.1% (95% CI: 92.1% - 95.6%)
ppv: 70.3% (95% CI: 62.5% - 77.2%)
npv: 99.0% (95% CI: 97.9% - 99.5%)

Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.

Great Basin Scientific Portrait Toxigenic C. Difficile Assay - K113358

Reference Device(s):

Not Found

Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).

Not Found

§ 866.3130 Clostridium difficile toxin gene amplification assay.

(a)
Identification. AClostridium difficile toxin gene amplification assay is a device that consists of reagents for the amplification and detection of target sequences inClostridium difficile toxin genes in fecal specimens from patients suspected of havingClostridium difficile infection (CDI). The detection of clostridial toxin genes, in conjunction with other laboratory tests, aids in the clinical laboratory diagnosis of CDI caused byClostridium difficile. (b)
Classification. Class II (special controls). The special controls are set forth in FDA's guideline document entitled: “Class II Special Controls Guideline: Toxin Gene Amplification Assays for the Detection ofClostridium difficile; Guideline for Industry and Food and Drug Administration Staff.” See § 866.1(e) for information on obtaining this document.

0

Image /page/0/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white, with the word "QUIDEL" in large, bold letters. The word "CORPORATION" is written in smaller letters below the main word. There is a registered trademark symbol to the right of the word Quidel.

DECISION Quidel AmpliVue™ C. difficile Assay 510(k) SUMMARY

A. 510(k) Number:

K123355

B. Date of Preparation:

December 10, 2012

C. Purpose for Submission:

To determine substantial equivalence of the AmpliVue™ C. difficile Assay for the qualitative detection of toxigenic Clostridium difficile directly from unformed stool samples.

D. Measurand:

A fragment from the conserved 5' end of the Toxin A (tcdA) gene, located within the PaLoc of toxigenic Clostridium difficile strains.

E. Type of Test:

Qualitative, in vitro diagnostic nucleic acid amplification test; based on the isothermal, helicasedependent amplification (HDA) scheme combined with a manual read of assay results.

F. Applicant:

QUIDEL Corp.

G. Proprietary and Established Names:

AmpliVue™ C. difficile Assay

H. Regulatory Information:

1. Regulation section:

21 CFR 866.3130 - C. difficile Nucleic Acid Amplification Test Assay

10165 McKellar Court • San Diego • California 92121 858.552.1100 • Fax 858.453.4338 www.quidel.com

1

QUIDEL®
CORPORATION

    1. Classification: ·
      ll
    1. Product code:
      OZN - Amplification assay for the detection of Clostridium difficile toxin genes from stool specimens of symptomatic patients
    1. Panel:
      Microbiology (83)
  • l. Intended Use:

    • Intended use(s): 1.

The AmpliVue™ C. difficile Assay is an in vitro diagnostic test for the direct, qualitative detection of the Clostridium difficile Toxin A gene (tcdA) in unformed stool specimens of patients suspected of having Clostridium difficile-associated disease (CDAD). The AmpliVue™ C. difficile Assay is intended for use as an aid in diagnosis of CDAD. The assay utilizes helicase-dependent amplification (HDA) for the amplification of a highly conserved fragment of the Toxin A gene sequence and a self-contained disposable amplicon device that allows for manual evaluation of assay results.

    1. Indication(s) for use:
      Same as Intended Use.
    1. Special conditions for use statement(s):
      For prescription use only.
    1. Special instrument requirements:
      None, detection is by manual read.

J. Device Description:

` The AmpliVue™ C. difficile Assay combines simple specimen processing, an isothermal amplification technology named helicase-dependent amplification (HDA), and a self- contained disposable amplicon detection device for the detection of Clostridium difficile directly from CDAD-suspected stool specimens.

2

Image /page/2/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in a bold, sans-serif font. Below the word "QUIDEL" is the word "CORPORATION" in a smaller, sans-serif font. The logo is simple and modern.

A swab is used to transfer a small amount of specimen into a dilution tube. The diluted sample is then transferred into a sample lysis buffer tube, and the cells are lysed by simple heat treatment. After heat treatment, an aliquot of the lysed sample is added to a reaction tube containing a lyophilized mix of HDA reagents, including primers specific for the amplification of a fragment from the conserved 5' end of the tcdA gene that are located within the PaLoc of toxigenic C. difficile strains. The assay also includes a process control to monitor specimen processing and to confirm the integrity of the assay reagents and cassette detection, as well as to assess for HDA-inhibitors that may be present within the stool specimen. Competitive amplification of the process control DNA also takes place unless inhibitory substances are present or the specimen processing fails. The HDA reaction is asymmetric so that an excess of single stranded DNA is formed from a biotinylated primer present within the reaction mix. The capture probes for each amplicon bind to the corresponding biotinylated single-stranded DNA forming dual labeled amplicons.

After completion of the HDA reaction, the reaction tube is transferred to a single-use, disposable cassette for detection. The self-contained cassette is comprised of two individual components: an amplicon cartridge that holds the running buffer and the single 0.2-ml thin wall reaction tube containing the amplified product. The detection chamber houses the amplicon cartridge and a vertical-flow DNA detection strip embedded into the cassette. The DNA detection strip is coated with an anti-FITC antibody and an anti-DNP antibody that serve as the C. difficile test (T2) line and the control (C) line in the assay, respectively. A razor blade and a plastic pin located at the bottom of the detection chamber opens the HDA reaction tube and the running buffer bulb when the handle of the detection chamber is closed.

The mixture flows through a fiberglass paper connected to the DNA detection strip that contains a fiberglass pad pre-loaded with streptavidin-conjugated color particles for color visualization. The dual-labeled probe-amplicon hybrid is then detected by the lateral flow strip within the cassette. The bottom line captures the FITC-labeled probe-amplicon and the top line captures the DNPlabeled probe-amplicon. The biotin label attracts the streptavidin-conjugated color particles for visualization and the test result is shown as colored lines visible to the naked eye. Detection of C. difficile DNA is reported when the T2 and C lines are visible through the detection window of the cassette. No detection of C. difficile DNA is reported when only the C line is displayed. The assay is regarded as unresolved when neither line is displayed. The whole procedure takes approximately 75 minutes (Note: The T1 line present on the self-contained cassette is for a triplex assay and is not applicable/used for the AmpliVue C. difficile Assay).

The Quidel AmpliVue C. difficile Assay contains sufficient reagents to process 16 specimens or quality control samples. The kit contains the following:

3

Image /page/3/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in large, bold letters. Below the word "QUIDEL" is the word "CORPORATION" in smaller letters. The logo is simple and professional.

ComponentQuantityStorage
Detection Cassettes: Each cassette comes
preloaded with all required probes and signal
amplification solutions necessary to generate a test
result.16/kit2° to 30°C
Dilution Buffer: Ready for use.16 tubes/kit 1.8 mL2° to 8°C
Lysis Buffer: Ready for use.16 tubes/kit 1 mL2° to 8°C
Reaction Tubes: Ready for use.16 tubes/kit2° to 8°C
Amplicon Cartridge: Each cartridge comes
preloaded with all solutions required amplification.16/kit2° to 30°C
Flocked Swabs: Ready for use.16 swabs/kit2° to 30°C

K. Substantial Equivalence Information:

    1. Predicate device name(s):
      Great Basin Scientific Portrait Toxigenic C. Difficile Assay

2. Predicate 510(k) number(s):

Great Basin Scientific Portrait Toxigenic C. Difficile Assay - K113358

Comparison with predicate: ന്

Similarities
ItemDevicePredicate (Great Basin
Scientific Portrait Toxigenic C.
Difficile Assay)
Intended UseThe AmpliVue™ C. difficile
Assay is an in vitro diagnostic
test for the direct, qualitative
detection of the Clostridium
difficile Toxin A gene (tcdA) in
unformed stool specimens of
patients suspected of havingPortrait Toxigenic C. difficile
Assay, a prescription device
under 21 CFR Part 801.109
that is indicated for the
detection of toxigenic
Clostridium difficile in human
fecal samples collected from
patients suspected of having

4

Image /page/4/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in large, bold letters. Below the word "QUIDEL" is the word "CORPORATION" in smaller letters. There is a registered trademark symbol to the right of the word "QUIDEL".

. .

.

Similarities
ItemDevicePredicate (Great Basin
Scientific Portrait Toxigenic C.
Difficile Assay)
associated disease (CDAD).
The AmpliVue™ C. difficile
Assay is intended for use as
an aid in diagnosis of CDAD.
The assay utilizes helicase-
dependent amplification
(HDA) for the amplification of
a highly conserved fragment
of the Toxin A gene sequence
and a self-contained
disposable amplicon
detection device that allows
for manual evaluation of
assay results.Clostridium difficile infection
(CDI). The test utilizes
automated blocked primer
enabled helicase-dependent
amplification (bpHDA) to
detect toxin gene sequences
associated with toxin
producing C. difficile. The
Portrait Toxigenic C. difficile
Assay is intended as an aid in
the diagnosis of CDI.
SpecimenUnformed stoolSame
Assay time75-90 minsame
Test CartridgeDisposable, single-use, multi-
chambered fluidic cartridge.Same
Technological principleNucleic acid amplificationSame
Assay techniqueIsothermal, helicase-
dependent nucleic acid
amplificationSame
Differences
ItemDevicePredicate
AnalyteToxin A gene ( tcdA )Toxin B gene ( tcdB )
Detection
technique/instrumentThe HDA reaction generates a
biotinylated amplicon for
both the target ( tcdA ) and the
internal control. CaptureAmplification primers are
biotin-labeled primers and
hybridized to probes
immobilized on a silicon chip.
Differences
ItemDevicePredicate
probes specifically bind to the
corresponding biotinylated
single-stranded DNA forming
dual labeled amplicons. The
reaction tube containing this
mixture is transferred to a
single-use, disposable
cassette for detection. The
mixture flows through a
fiberglass paper connected to
the DNA detection strip that
contains a fiberglass pad pre-
loaded with streptavidin-
conjugated color particles for
color visualization. The dual-
labeled probe-amplicon
hybrid is then detected by the
lateral flow strip within the
cassette. The bottom line
captures the FITC-labeled
probe-amplicon and the top
line captures the DNP-labeled
probe-amplicon. The biotin
label attracts the
streptavidin-conjugated color
particles for visualization and
the test result is shown as
colored lines visible to the
naked eye.Incubation with anti-biotin
antibody conjugated to the
HRP with TMB allows
visualization by Portrait
Analyzer
Detection methodManualAutomated

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Image /page/5/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in large, bold letters. Below the word "QUIDEL" is the word "CORPORATION" in smaller letters. The logo is simple and professional.

L. Standard/Guidance Document Referenced (if applicable):

"Establishing the Performance Characteristics of In Vitro Diagnostic Devices for the Detection of Clostridium difficile." DRAFT Guidance - November 29, 2010

.

6

Image /page/6/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in large, bold letters. Below the word "QUIDEL" is the word "CORPORATION" in smaller letters. The logo is simple and professional.

M. Test Principle:

The AmpliVue™ C. difficile Assay combines simple specimen processing, an isothermal amplification technology named helicase-dependent amplification (HDA), and a self- contained disposable amplicon detection device for the detection of Clostridium difficile directly from CDAD-suspected stool specimens.

A swab is used to transfer a small amount of specimen into a dilution tube. The diluted sample is then transferred into a sample lysis tube and the cells are lysed by simple heat treatment. After heat treatment an aliquot of the lysed sample is added to a reaction tube containing lyophilized mix of HDA reagents including primers specific for the amplification of a fragment from the conserved 5' end of the tcdA gene, located within the PaLoc of toxigenic C. difficile strains. The assay also includes a process control to monitor sample processing and to confirm the integrity of the assay reagents and cassette detection as well as assay for HDA-inhibitors that may be present within the diarrheal sample. After completion of the HDA reaction tube is transferred to a disposable lateral flow detection cassette for rapid detection with test result displayed as test and/or control lines in the window of the detection cassette. The whole procedure takes approximately 75 minutes, depending on the number of specimens processed.

N. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

Precision: For the Precision/Within Laboratory Repeatability study, a blinded four-member panel consisting of C. difficile positive and negative sample was tested by two operators, twice a day using a single assay lot of AmpliVue C. difficile Assay for thirteen (13) days.

7

Image /page/7/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in large, bold letters. Below the word "QUIDEL" is the word "CORPORATION" in smaller letters. There is a registered trademark symbol to the right of the word Quidel.

CategoryOperator #1Operator #2Overall Percent Agreement95% Confidence Interval
#expected
results/# tested% Agreement#expected
results/# tested% Agreement
C. difficile High Negative
(T2-/C+; 20-80%)0/240%0/240%0/480%0% - 8%
C. difficile Low Positive
(T2+/C+, ≥95%)24/24100%24/24100%48/48100%91.2% - 100%
C. difficile Moderate Positive
(T2+/C+, ≥95%)24/24100%24/24100%48/48100%91.2% - 100%
Negative
(T2-/C+, 100%)24/24100%24/24100%48/48100%91.2% - 100%
C. difficile Positive Control24/24100%24/24100%48/48100%91.2% - 100%
Assay Negative Control24/24100%24/24100%48/48100%91.2% - 100%
  1. September 1999

:

.

8

Image /page/8/Picture/0 description: The image shows the logo for Quidel Corporation. The logo is in black and white and features the word "QUIDEL" in large, bold letters. Below the word "QUIDEL" is the word "CORPORATION" in smaller letters. The logo is simple and clean, and it is likely used on the company's website and marketing materials.

Reproducibility: In order to confirm the reproducibility of the AmpliVue™ C. difficile Assay a blinded and randomized study panel containing Clostridium difficile negative and positive samples were tested at three (3) test sites, two of which were clinical sites. Each site tested a reproducibility panel and assay controls for five (5) days in triplicate. The testing was done by two operators at each site. Each operator ran the panel once a day using one lot of AmpliVue™ C. difficile Assay.

| Category | Site #1 | | Site #2 | | Site #3 | | Overall Percent
Agreement | | 95% Confidence
Interval |
|-----------------------------------|----------------------------------|-------------|----------------------------------|-------------|-------------------------------|-------------|------------------------------|------|----------------------------|
| | #expected
results/#
tested | % Agreement | #expected
results/#
tested | % Agreement | #expected
results/# tested | % Agreement | | | |
| C. difficile High
Negative | 25/30 | 83% | 23/30 | 77% | 24/30 | 80% | 72/90 | 80% | 71% - 87% |
| C. difficile Low
Positive | 30/30 | 100% | 29/29 | 100% | 30/30 | 100% | 89/89* | 100% | 95% - 100% |
| C. difficile
Moderate Positive | 30/30 | 100% | 30/30 | 100% | 30/30 | 100% | 90/90 | 100% | 95% - 100% |
| Negative | 30/30 | 100% | 30/30 | 100% | 30/30 | 100% | 90/90 | 100% | 95% - 100% |
| C. difficile Positive
Control | 30/30 | 100% | 30/30 | 100% | 30/30 | 100% | 90/90 | 100% | 95% - 100% |
| Assay Negative
Control | 30/30 | 100% | 30/30 | 100% | 30/30 | 100% | 90/90 | 100% | 95% - 100% |
| Lot# | CLIN-005 | | | | | | | | |

Note: One (1) sample was invalid.

b. Linearity/assay reportable range:

N/A

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Controls: C.

The AmpliVue C. difficile assay incorporates a process control which is included in the lysis buffer tube and is used to monitor sample processing and evaluates the presence of inhibitory substances. The process control confirms the integrity of assay reagents and cassette detection. Additional controls are performed in accordance with end user laboratory guidelines and requirements.

Detection limit: d.

The analytical sensitivity (limit of detection or LoD) of the Quidel AmpliVue C. difficile Assay was determined using quantified (CFU/mL) cultures of two C. difficile strains (ATCC 43255 {toxinotype 0} and CCUG 8864 {toxinotype X}) serially diluted in a negative fecal matrix. Analytical sensitivity (LoD) is defined as the lowest concentration at which 95% of all replicates tested positive.

StrainToxinotypeLoD (CFU/ Assay)
ATCC 4325504.2
CCUG 8864×0.7

The final assay LoD is defined as the higher of the two strain concentrations where 95% positivity was observed. The final assay LoD is 4.2 CFU/assay.

Analytical Reactivity (Inclusivity) e.

Twenty-four toxigenic strains for C. difficile were tested at 2 to 3x LoD in negative specimen matrix using three (3) AmpliVue C. difficile assay lots. Strains were reported to originate from at least five states and four countries (USA, Belgium, France and Sweden). Seven (7) toxinotypes were represented: 0, Illb, IIIc, IV, V, VIII and XXIII. The analytical reactivity (inclusivity) testing conducted demonstrated that the AmpliVue C. difficile assay can detect a broad range of toxigenic Clostridium difficile strains.

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Analytical specificity: f.

Cross Reactivity

The analytical specificity of the Quidel AmpliVue C. difficile Assay was evaluated by testing a panel consisting of sixty-six (66) bacterial, viral and yeast microorganisms and human DNA representing common enteric pathogens, flora or nucleic acid commonly present in the intestine. Microorganisms or nucleic acid was mixed with pooled negative matrix and tested directly or in the presence of 2 to 3x LoD level of C. difficile for cross reactivity and microbial interference, respectively. Bacteria were tested at concentrations greater than 1.0E+06 CFU/mL and viruses at greater than 1.0E+05 PFU/mL. In addition, in silico analysis showed that the AmpliVue C. difficile Assay had no predicted cross-reactivity for C. botulinum. The results of this study demonstrate that the AmpliVue C. difficile Assay does not cross react with medically relevant levels of viruses or bacteria found in stool specimens.

Interfering Substances

Two toxigenic strains of C. difficile (ATCC 43255, toxinotype 0; CCUG 8864, toxinotype X) were evaluated against a test panel consisting of thirty-four substances found in stool specimens. Substances were introduced into the assay dilution tubes at concentrations which were medically relevant. Each of the strains was tested for each substance. None of the substances tested were found to interfere with the AmpliVue C. difficile Assay.

Assay cut-off: g.

N/A

    1. Comparison studies:
      Method comparison with predicate device: a.

The performance of the AmpliVue C. difficile Assay was evaluated at four geographically diverse locations within the United States between January 2012 and October 2012. Eight hundred and forty (840) samples were tested by both the AmpliVue C. difficile Assay and the Tissue Culture Cytotoxicity Assay. One specimen (0.1%) was indeterminate in the cytotoxin assay due to toxicity in the antitoxin well. Four specimens (0.5%) were invalid in the AmpliVue C. difficile Assay when initially tested. Three (3) of these specimens yielded valid results (all were negative) when retested according to the AmpliVue C. difficile Assay's instructions for use. One (1) specimen remained invalid upon repeat testing. The data below is based on the initial result for the eight hundred and thirty-five (835) specimens.

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| Tissue Culture

Cytotoxin95% CI
POSNEGTotalSensitivity93.6%87.3%96.9%
AmpliVue C. difficilePOS10243*145Specificity94.1%92.1%95.6%
NEG7**683690ppv70.3%62.5%77.2%
Total109726835npv99.0%97.9%99.5%
  • Of these forty three (43) discordant specimens (AmpliVue Positive/Tissue Culture Cytotoxin Negative) reported, thirty-seven (37) were positive for C. difficile by a FDA-cleared molecular device, and six (6) were negative.

** Of these seven (7) discordant specimens (AmpliVue Negative/Tissue Culture Cytotoxin positive) reported, two (2) were positive for C. difficile by a FDA-cleared molecular device, and five (5) were negative.

The distribution of positive specimens is parsed by gender and age below (incidence based on results from the AmpliVue C. difficile Test):

MaleFemaleTotal
AgenAmpliVue+%nAmpliVue+%nAmpliVue+%
21 and ≤591662515.1%1672615.6%3335115.3%
≥601342518.7%2063818.4%3406318.5%
Total3947017.8%4417517.0%83514517.4%
  • b. Matrix comparison:
    N/A

    1. Clinical studies:
    • a. Clinical Sensitivity:

N/A

  • b. Clinical specificity:

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QUIDEL
CORPORATION

N/A

  • Other clinical supportive data (when a. and b. are not applicable): ن
    N/A

  • Clinical cut-off: ধ:
    N/A

    1. Expected values/Reference range:
      N/A

O. Proposed Labeling:

The labeling is per the requirements of 21 CFR Part 809.10.

P. Conclusion:

Quidel has submitted this 510(k) in accordance with the requirements of SMDA 1990 and 21 CFR 807.92. This summary of 510(k) safety and effectiveness information provides the necessary detail for a determination of substantial equivalence for the Quidel AmpliVue™ C. difficile Assay.

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K123355

Decision Summary, K123355

This 510(k) was reviewed under OIR's Pilot Triage Program. This program represents an internal workload management tool intended to reduce internal FDA review resources for 510(k) applications that are of good quality upon receipt by FDA.

The information in the 510(k) is complete and supports a substantial equivalence (SE) determination. Please refer to the applicant's 510(k) summary for a summary of the information that supports this SE determination.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

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Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-002

Quidel Corporation Mr. Ron H. Lollar 10165 McKellar Court San Diego, California 92121

EC 1 3 2012

Re: K123355

Trade/Device Name: Regulation Number: Regulation Name: Regulatory Class: Product Code: Dated: Received:

AmpliVue™ C. difficile Assay 21 CFR 866.3130 C. Difficile Nucleic Acid Amplification Test Assay Class II OZN October 26, 2012 November 6, 2012

Dear Mr. Lollar:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 - Ron H. Lollar

If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostics and Radiological Health at (301) 796-5450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office

of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrl/industry/support/index.html.

Sincerely yours,

Sally A. Hojvat

Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

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510(k) Number K123355:

Device Name: AmpliVue™ C. difficile Assay

Indication for Use:

The AmpliVue™ C. difficile assay is an in vitro diagnostic test for the direct, qualitative detection of the Clostridium difficile Toxin A gene (tcdA) in unformed stool specimens of patients suspected of having Clostridium difficile-associated disease (CDAD). The AmpliVue™ C. difficile assay is intended for use as an aid in diagnosis of CDAD. The assay utilizes helicase-dependent amplification (HDA) for the amplification of a highly conserved fragment of the Toxin A gene sequence and a self-contained disposable amplification detection device that allows for manual evaluation of assay results.

Prescription Use X (Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Counter Use (21 CFR 801 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED

Concurrence of CDRH, Office of Device Evaluation (ODE)

Soy at
Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

K 123355 510(k)