(592 days)
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No
The device description details a standard enzyme immunoassay with fluorometric detection, and there are no mentions of AI, ML, or related concepts in the provided text.
No
The device is an in vitro diagnostic test kit intended to measure total thyroxine (T4) in blood samples, which is a diagnostic function, not a therapeutic one.
Yes
Explanation: The device is intended "for use in determining the total thyroxine (T4) in blood specimens," which is a diagnostic measurement.
No
The device description clearly outlines a chemical assay kit involving reagents, incubation steps, and measurement with a fluorometer, indicating it is a hardware-based diagnostic test kit, not software only.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The intended use is "determining the total thyroxine (T4) in blood specimens dried on filter paper." This clearly indicates that the device is used to examine specimens derived from the human body (blood) to provide information for diagnostic purposes (determining T4 levels).
- Device Description: The description details a "sequential, competitive enzyme immunoassay with fluorometric detection." This describes a laboratory test method performed in vitro (outside the body) on a biological sample.
- Specimen Type: The device uses "blood specimens dried on filter paper," which are biological samples taken from the human body.
These characteristics align directly with the definition of an In Vitro Diagnostic device.
N/A
Intended Use / Indications for Use
Isolab's T4 Test Kit is intended for use in determining the total thyroxine (T4) in blood specimens dried on filter paper.
Product codes (comma separated list FDA assigned to the subject device)
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Device Description
The Isolab's T4 Test Kit is a sequential, competitive enzyme immunossay with fluorometric detection in which T4 is eluted from dried blood disks and simultaneously forms a complex with the biotin-labeled monoclonal antibody which binds to the streptavidin coated solid phase. After sufficient incubation with biotinylated antibody, a conjugate of T4 with horseradish peroxidase is added to the wells and incubated with the reaction mixture. This conjugate competes with the analyte for the free on the bound monoclonal antibody. Excess of unbound reagent is washed away after a sequential incubation with biotinylated antibody and conjugate, and the enzymatic reaction with a fluorogenic substrate 3-phydroxyphenylpropionic acid (HPPA) [9] takes place. The reaction is stopped by addition of glycine buffer and the fluorescence in each well is measured with Fluoroscan II Neonate at 405 nm (excitation being 320 nm).
Isolab has two kit sizes available for the T4 Test Kit. Test Kit NT-1000 contains enough reagents and Microstrips to run 800 patient samples. Additonal wells are available for Calibrators and controls. Test Kit NT-4000 contains enough reagents and coated Microstrips to run 4000 patient samples. Additonal wells are available for Calibrators and Controls.
Mentions image processing
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Mentions AI, DNN, or ML
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Input Imaging Modality
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Anatomical Site
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Indicated Patient Age Range
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Intended User / Care Setting
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Description of the training set, sample size, data source, and annotation protocol
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Description of the test set, sample size, data source, and annotation protocol
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Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Linearity:
Results of the linearity study show that the assay is linear from concentration of 0 to 25 ug/dL of T4. Concentrations of T4 in the amounts of 6.25, 12.5, and 25 ug/dL were added to a whole blood sample and spotted onto filter Schleicher & Schuell No. 903 paper. Each spiked sample along with the unspiked sample was run five times.
Recovery:
The recovery was determined from the same data as shown under Reproducibility. The recovery can be calculated by the following formula:
mean / amount added X 100 = % recovery
6.25 µg/dL X 100 = 88%
12.5 µg/dL X 100 = 97%
The recovery is shown at the low T4 levels to be around 88% and at normal levels around 97%.
Sensitivity:
The detection limit for the T4 assay 1.0 ug/dL.
Reproducibility:
Two sample pools were run in duplicate twice a day for 20 days.
T4 depleted neonate: amount added 6.25 µg/dL, mean 5.5 µg/dL, total SD 0.57, total CV 10.4%, within-run SD 0.43, within-run CV 7.8%
Normal neonate: amount added 12.5 µg/dL, mean 12.1 µg/dL, total SD 1.89, total CV 15.6%, within-run SD 1.52, within-run CV 12.6%
Comparison of Methods:
Isolab's T4 Test Kit was compared to Neometric's Accuscreen T4 and Wallac Oy's Delphia Neonatal T4. The values for the Neometrics and Wallac Oy assays were performed at two state laboratory facilities.
Isolab: State 1 Cutoff (µg/dL) 8.5, State 2 Cutoff (µg/dL) 8.1
Neometrics: State 1 Cutoff (µg/dL) -, State 2 Cutoff (µg/dL) 11.7
Wallac Oy: State 1 Cutoff (µg/dL) 10.2, State 2 Cutoff (µg/dL) -
The distribution of values as well as the mean values, standard deviations and median values for the Isolab methods and the two comparative rest kit methods are shown on the next page.
Interference testing:
Interference testing was designed and executed using NCCLS document EP-7 as guidance [14]. The following substances were added to a control sample and tested as possible interferents to the T4 Test Kit. The control sample was assayed seven times and each of the whole spiked with the following substances were also assayed seven times. The two thyroxines (D-T4) added about 100% to the calculated values as expected. Two other thyroxine anologs (DL-T and TA3) also produced a slight interference. The drug, 5-propyl-2-thiouracil (PTU) also caused a slight interference at the concentration tested. This level would probably be higher than in a neonate on this drug.
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Sensitivity: The detection limit for the T4 assay 1.0 ug/dL.
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.
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Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.
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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).
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§ 862.1700 Total thyroxine test system.
(a)
Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.
0
ISOLAB INC.
510(K)
T4 TEST KIT EXHIBIT C
Summary of Safety and Effectiveness
OCT 18 1996
Isolab's T4 Test Kit is intended for use in determining the total thyroxine (T4) in blood specimens dried on filter paper.
The Isolab's T4 Test Kit is a sequential, competitive enzyme immunossay with fluorometric detection in which T4 is eluted from dried blood disks and simultaneously forms a complex with the biotin-labeled monoclonal antibody which binds to the streptavidin coated solid phase. After sufficient incubation with biotinylated antibody, a conjugate of T4 with horseradish peroxidase is added to the wells and incubated with the reaction mixture. This conjugate competes with the analyte for the free on the bound monoclonal antibody. Excess of unbound reagent is washed away after a sequential incubation with biotinylated antibody and conjugate, and the enzymatic reaction with a fluorogenic substrate 3-phydroxyphenylpropionic acid (HPPA) [9] takes place. The reaction is stopped by addition of glycine buffer and the fluorescence in each well is measured with Fluoroscan II Neonate at 405 nm (excitation being 320 nm).
Isolab has two kit sizes available for the T4 Test Kit. Test Kit NT-1000 contains enough reagents and Microstrips to run 800 patient samples. Additonal wells are available for Calibrators and controls. Test Kit NT-4000 contains enough reagents and coated Microstrips to run 4000 patient samples. Additonal wells are available for Calibrators and Controls.
| Code | Code | Description |
|---|---|---|
| NT-1000 | NT-4000 | Item |
| 10 plates | 50 plates | Streptavidin coated Microstrips® |
| 2 x 90 ml | 10 x 90 ml | Biotinylated Antibody (Bottle 1) |
| 2 X 30 ml | 10 X 30 ml | T4-HRP Conjugate (Bottle 2) |
| 210 ml | 5 X 210 ml | HPPA Substrate |
| (Bottle 3) | ||
| 45 ml | 5 X 45 ml | H2O2 Solution |
| (Bottle 4) | ||
| 200 ml | 2 X 500 ml | Stopping Solution |
| (Bottle 5) | ||
| 220 ml | 2 X 500 ml | Wash Solution |
| (Bottle 6) | ||
| 1 card | 5 cards | T4 Calibrators |
| 10 | 50 | Microstrip Covers |
| (Plastic sheets to cover the | ||
| Microstrips® during incubation.) |
The T4 values given for the Controls, Calibrators and thus patient results are given in ug/dL. This unit of measure reflects the estimated amount that would be found in serum. These values should be considered accurate for the purposes of screening. Due to differences in hematocrit values, these values should not be assumed as accurate as those from serum-based assays. The discrimination between normal and presumptive positives for CH is based on a predetermined fixed cut-off value generally regarded to be based on the lower 10%. The cut-off value that represents the lower 10% for this assay is 8.5 µe/d! Anv result at this value or below should be confirmed by another diagnestic test or procedure to confirm that the patient is positive for congenital hypothyrcidism.
Linearity
Results of the linearity study show that the assay is linear from concentration of 0 to 25 ug/dL of T4. Concentrations of T4 in the amounts of 6.25, 12.5, and 25 ug/dL were added to a whole blood sample and spotted onto filter Schleicher & Schuell No. 903 paper. Each spiked sample along with the unspiked sample was run five times.
1
Recovery
The recovery was determined from the same data as shown under Reproducibility. The recovery can be calculated by the following formula:
mean
X 100
= % recovery
amount added
వ్.వ X 100 = 88% 6.25 12.1 X 100 = 97% 12.5 The recovery is shown at the low T4 levels to be around 88% and at normal levels around 97%.
Sensitivity
The detection limit for the T4 assay 1.0 ug/dL.
Reproducibility
Two sample pools were run in duplicate twice a day for 20 days. The summary of the results are shown:
| | amount
added | mean | total
SD | total
CV | within-
run SD | within-
run CV |
|---------------------------|-----------------|---------------|-------------|-------------|-------------------|-------------------|
| T4
depleted
neonate | 6.25
µg/dL | 5.5
µg/dL | 0.57 | 10.4% | 0.43 | 7.8% |
| normal
neonate | 12.5
µg/dL | 12.1
µg/dL | 1.89 | 15.6% | 1.52 | 12.6% |
Comparison of Methods
Isolab's T4 Test Kit was compared to Neometric's Accuscreen T4 and Wallac Oy's Delphia Neonatal T4. The values for the Neometrics and Wallac Oy assays were performed at two state laboratory facilities. the lower 10% of the values for each of the assays are shown.
| Test | State 1 Cutoff
(µg/dL) | State 2 Cutoff
(µg/dL) |
|------------|---------------------------|---------------------------|
| Isolab | 8.5 | 8.1 |
| Neometrics | - | 11.7 |
| Wallac Oy | 10.2 | - |
The distribution of values as well as the mean values, standard deviations and median values for the Isolab methods and the two comparative rest kit methods are shown on the next page.
2
Image /page/2/Figure/0 description: The image contains two bar charts that compare the distribution of T4 values. The chart on the left compares Isolab and Wallack, while the chart on the right compares T4 Neometrics and Isolab distribution. Both charts show the frequency of T4 values in different ranges, with the x-axis representing T4 levels in ug/dL and the y-axis representing frequency. The charts also include tables with statistical data such as mean, standard deviation, and median for each group.
Interference testing was designed and executed using NCCLS document EP-7 as guidance [14]. The following substances were added to a control sample and tested as possible interferents to the T4 Test Kit. The control sample was assayed seven times and each of the whole spiked with the following substances were also assayed seven times. The two thyroxines (D-T4) added about 100% to the calculated values as expected. Two other thyroxine anologs (DL-T and TA3) also produced a slight interference. The drug, 5-propyl-2-thiouracil (PTU) also caused a slight interference at the concentration tested. This level would probably be higher than in a neonate on this drug.