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The BD ProbeTecT™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay, when tested with the BD Viper™ System in Extracted Mode, uses Strand Displacement Amplification technology for the direct, qualitative detection of Neisseria gonorrhoeae DNA in clinician-collected female endocervical and male urethral swab specimens, patient-collected vaginal swab specimens (in a clinical setting), and male and female urine specimens (both UPT and Neat). The assay is also intended for use with gynecological specimens collected in BD SurePath™ Preservative Fluid using an aliquot that is removed prior to processing for the BD SurePath™ Pap test. The assay is indicated for use with asymptomatic and symptomatic individuals to aid in the diagnosis of gonococcal urogenital disease.

The BD ProbeTec GC O* Amplified DNA Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe. The reagents for SDA are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification, while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. The BD Viper™ System pipettes a portion of the purified DNA solution from each Extraction Tube into a Priming Microwell to rehydrate the contents. After a brief incubation, the reaction mixture is transferred to a corresponding, pre-warmed Amplification Microwell which is sealed to prevent contamination and then incubated in one of the two thermally-controlled fluorescent readers. The presence or absence of N. gonorrhoeae DNA is determined by calculating the peak fluorescence (Maximum Relative Fluorescent Units (MaxRFU)) over the course of the amplification process and by comparing this measurement to a predetermined threshold value.

In addition to the fluorescent probe used to detect amplified N. gonorrhoeae target DNA, a second labeled oligonucleotide is incorporated in each reaction. The Extraction Control (EC) oligonucleotide is labeled with a different dye than that used for detection of the N. gonorrhoeae -specific target and is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is rehydrated upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the BD Viper System and an automated algorithm is applied to both the EC and N. gonorrhoeae -specific signals to report results as positive, negative, or EC failure.

BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay

1. Table of Acceptance Criteria and Reported Device Performance

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The BD ProbeTec Chlamydia trachomatis (CT) Q* Amplified DNA Assay, when tested with the BD Viper™ System in Extracted Mode, uses Strand Displacement Amplification (SDA) technology for the direct, qualitative detection of Chlamydia trachomatis DNA in cliniciancollected female endocervical and male urethral swabs, patient-collected vaginal swab specimens (in a clinical setting), and female and male urine specimens. The assay is indicated for use with asymptomatic and symptomatic individuals to aid in the diagnosis of chlamydial urogenital disease.

The BD ProbeTec CT Q Amplified DNA Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe. The reagents for SDA are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification, while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. The BD Viper™ System pipettes a portion of the purified DNA solution from each Extraction Tube into a Priming Microwell to rehydrate the contents. After a brief incubation, the reaction mixture is transferred to a corresponding, pre-warmed Amplification Microwell which is sealed to prevent contamination and then incubated in one of the two thermallycontrolled fluorescent readers. The presence or absence of C. trachomatis DNA is determined by calculating the peak fluorescence (Maximum Relative Fluorescent Units (MaxRFU)) over the course of the amplification process and by comparing this measurement to a predetermined threshold value.

In addition to the fluorescent probe used to detect amplified C. trachomatis target DNA, a second labeled oligonucleotide is incorporated in each reaction. The Extraction Control (EC) oligonucleotide is labeled with a different dye than that used for detection of the C. trachomatis-specific target and is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is rehydrated upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the BD Viper System and an automated algorithm is applied to both the EC and C. trachomatis-specific signals to report results as positive, negative, or EC failure.

Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:

BD ProbeTec™ Chlamydia trachomatis (CT) Q* Amplified DNA Assay

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined "acceptance criteria" with numerical targets for sensitivity and specificity. Instead, it presents the results of clinical performance studies, implying that these results met the internal or regulatory expectations for substantial equivalence. For a medical device, the ultimate acceptance criterion for performance is typically demonstrating substantial equivalence to a legally marketed predicate device through clinical performance.

However, based on the clinical performance table, we can infer the achieved performance:

Analytical Sensitivity (Limit of Detection):

• ≤ 15 CT elementary bodies (EB) per mL for neat and UPT treated urine (serovar H)
• ≤ 30 CT EB per mL for expressed vaginal and endocervical swab specimens (serovar H)
• Able to detect 16 CT serovars with ≥ 95% proportion positive at 15 EB per mL in Q* Swab Diluent.

Analytical Specificity:

• Did not cross-react with any of the 141 organisms tested (Table 1 lists a comprehensive range of bacteria, viruses, and fungi).

Interfering Substances:

• No interference observed for a wide range of substances in swab and urine (Table 2).
• Potential for extraction control (EC) failures with blood (> 60%) in swabs.

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size (Clinical Performance Test Set):
  • Female Subjects: 994 compliant subjects (initially 1059 collected).
  • Male Subjects: 472 compliant subjects (initially 479 collected).
  • Total BD ProbeTec CT Q Assay results used for calculations:* 5388 individual assay results across various specimen types.
• Data Provenance:
  • Country of Origin: North America (United States is implied by the FDA submission, but "North America" is explicitly stated).
  • Retrospective or Prospective: Prospective. Subjects were recruited and specimens collected from OB/GYN, sexually transmitted disease (STD), and family planning clinics.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

The ground truth was established by a "patient infected status (PIS) algorithm" based on the results of two commercially available NAATs (Nucleic Acid Amplification Tests):

• BD ProbeTec ET CT/AC assay (predicate device, K984631)

• Another unspecified commercially available NAAT.

• Number of Experts: Not applicable in the traditional sense of human expert review. The ground truth was determined algorithmically by comparing results from the two reference NAATs.

• Qualifications of Experts: Not applicable, as the ground truth was based on the performance of existing, validated commercial assays rather than human expert opinion.

4. Adjudication Method for the Test Set

• Adjudication Method: Algorithmic consensus.
  • "Subjects were considered infected with CT if two of the four endocervical swab and urine specimens (or two of the three or four urethral swab and urine specimens) tested positive in the BD ProbeTec ET CT/AC assay AND the other reference NAAT (one specimen testing positive in each NAAT)." This effectively describes a 2/2 consensus or a complex majority rule across different specimen types and reference assays.
  • "Subjects were considered non-infected if less than two reference NAAT results were positive."

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

No, an MRMC comparative effectiveness study was not done. This device is an in-vitro diagnostic (IVD) assay where the result is generated by the instrument (BD Viper System) based on DNA amplification and detection, not by human readers interpreting images or data. The study compares the device's performance to established reference laboratory methods, not to human interpretation with or without AI assistance.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

Yes, the device's performance, as reported in the clinical performance section, is a standalone (algorithm only) performance. The BD ProbeTec CT Q* Amplified DNA Assay is an automated test performed on the BD Viper™ System. The system "monitors" fluorescence and applies an "automated algorithm" to report results (positive, negative, or EC failure). There is no human interpretation involved in generating the primary result for comparison to the ground truth.

7. The Type of Ground Truth Used

The ground truth used was a composite reference standard or patient infected status (PIS) algorithm based on the results of two other commercially available and legally marketed nucleic acid amplification tests (NAATs). It is not pathology, a definitive gold standard, or outcome data in the traditional sense, but a robust consensus based on highly sensitive and specific molecular methods.

8. The Sample Size for the Training Set

The document does not explicitly mention a separate "training set" or its sample size for the clinical performance evaluation. The clinical study described appears to be a validation study for the assay. For IVDs, "training" might refer to internal development and optimization phases, which are typically not detailed in 510(k) summaries. The data presented in the clinical performance section represents the results from the final, evaluated test set.

9. How the Ground Truth for the Training Set Was Established

As there is no explicitly defined "training set" presented in the document, information on how its ground truth was established is not available. The ground truth for the validation set was established using the PIS algorithm based on the two reference NAATs, as described in point 4.

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