For the qualitative and quantitative detection of human IgG antibodies to Rubella in human serum by enzyme immunoassay, to aid in the determination of infection with rubella virus. When used as a qualitative test, SeraQuest Rubella IgG aids in the assessment of the patient's immunological response to rubella. For manual use, or for use with the HyPrep System Plus.

Device Description

The SeraQuest™ Rubella IgG test is a solid-phase enzyme immunoassay (EIA), which is performed in microwells, at room temperature, in three thirty minute incubations. It has been developed to detect IgG antibodies which are directed against rubella virus, in human serum.

The Calibrators in the SeraQuest Rubella IgG test set have been assigned Index values based on an in-house standard, and International Unit values (IU / ml) which are traceable to the WHO International Reference Preparation of Anti-rubella Serum. Test results may be reported as Index values, or as IU / ml.

AI/ML Overview

Here's an analysis of the provided text, extracting the information requested for acceptance criteria and the study that proves the device meets them:

1. A table of acceptance criteria and the reported device performance

Based on the "Summary of Clinical Testing" section, the acceptance criteria are implied by the agreement rates, particularly the overall agreement excluding equivocal results.

Acceptance Criteria (Implied)	Reported Device Performance
Overall agreement with predicate device ≥ 95.2% (lower bound of 95% CI)	97.2% (95% Confidence Interval = 95.2 to 99.3) (excluding equivocal results)
Relative sensitivity with predicate device ≥ 94.3% (lower bound of 95% CI)	94.3 to 99.1 (95% CI)
Relative specificity with predicate device ≥ 95.4% (lower bound of 95% CI)	95.4 to 100 (95% CI)

2. Sample sized used for the test set and the data provenance

Sample Size: 260 sera
Data Provenance: "normal blood donors." The country of origin is not explicitly stated, but given the applicant's address (North Miami, FL), it's highly likely to be the USA. The data is retrospective, as the samples were collected and then tested.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not applicable. The "ground truth" for this study was established by comparing the device's results against a predicate device (INCSTAR Rubella IgG Clin-ELISA™ kit), not through expert interpretation of a gold standard.

4. Adjudication method for the test set

Not applicable. There was no expert adjudication process described, as the comparison was against a predicate device's results.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not applicable. This is a study for a diagnostic assay (SeraQuest™ Rubella IgG) for detecting antibodies, not an AI-assisted imaging or diagnostic tool involving human readers.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, this study is a standalone performance study. The SeraQuest™ Rubella IgG test is an enzyme immunoassay that produces objective results (absorbance readings converted to Index values or IU/ml), and its performance was evaluated without human intervention in the interpretation process beyond reading the instrument results.

7. The type of ground truth used

The "ground truth" for this study was the results obtained from a predicate device, the Rubella IgG Clin-ELISA™ kit from INCSTAR Corporation. This is a common approach for demonstrating substantial equivalence for new diagnostic assays.

8. The sample size for the training set

The document does not explicitly state a separate "training set" sample size. For an in vitro diagnostic assay like this, development often involves internal validation and optimization with various samples, but a formal distinction between a "training set" and "test set" in the machine learning sense is not typically documented in this type of submission. The 260 sera were used for the clinical validation/test set.

9. How the ground truth for the training set was established

As there's no explicitly defined "training set" in the context of this submission, this question is not fully applicable. However, the device itself was developed and calibrated using an "in-house standard" and International Unit values traceable to the WHO International Reference Preparation of Anti-rubella Serum. This process of using international standards and internal controls would form the basis of establishing "ground truth" during device development.

Summary

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510(k) SUMMARY

K961053

Applicant:	Quest International, Inc.1938 N.E. 148th TerraceNorth Miami, FL 33181	SEP - 4 1996
Registration No.	FDA form 2891 was submitted on April 1, 1995.
Contact Person:	Robert A. Cort, President
Telephone:	(305) 948-8788
Telefax:	(305) 948-4876
Manufacturing Site:	Same as above
Device:	SeraQuest™ Rubella IgG
Device Name:	Rubella serological reagents (21CFR § 866.3510)
Device Classification:	Class III (premarket approval)

scription:

Principle:

Diluted samples are incubated in rubella antigen-coated wells. Rubella antibodies (if present) are immobilized in the wells. Residual sample is eliminated by washing, and conjugate (enzyme-labeled antibodies to human IgG) is added and incubated. If IgG antibodies to rubella are present, the conjugate will be immobilized in the wells. Residual conjugate is eliminated by washing and draining, and the enzyme substrate is added and incubated. In the presence of the enzyme, the substrate is converted to a yellow end-product which is read photometrically.

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anded Use:

Predicate device:

The SeraQuest™ Rubella IgG test is substantially equivalent in intended use and performance, to the Rubella IgG Clin-ELISA™ kit, INCSTAR Corporation, Stillwater Minnesota.

Summary of technological characteristics:

Characteristic	SeraQuest™ Rubella IgG	INCSTAR Rubella IgG Clin-ELISA™
Description:	Enzyme Immunoassay	Enzyme Immunoassay
Intended Use:	The detection of IgGantibodies against Rubellain human serum.	The detection of IgGantibodies against Rubellain human serum.
Solid Phase:	Plastic Microwell	Plastic Microwell
Antigen Strain:	HPV 77	Not Stated in Package Insert
Number of Incubation Periods:	Three	Three
Sample Dilution:	1:50	1:50
Sample IncubationDuration:	30 minutes	30 minutes
Incubation Temperature:	Room temperature	Room temperature
Ezyme-labeled Conjugate:
Antibody	Goat anti-human IgG	Goat or Sheep anti-human IgG
Enzyme	Alkaline phosphatase	Alkaline phosphatase
Conjugate Volume:	100 µl	200 µl

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APPENDIX 8.	Quest International, Inc., 1938 N.E. 148th Terrace, N. Miami, FL 33181Page No.
njugate Incubation Duration:	30 minutes	30 minutes
Substrate:	p-Nitrophenyl phosphate	p-Nitrophenyl phosphate
Subtrate Volume:	100 μl	200 μl
Substrate Incubation Duration:	30 minutes	45 minutes
Stop Reagent:	0.5 M Trisodium phosphate	3 N Sodium Hydroxide
Stop Reagent Volume:	100 μl	50 μl
Readout:	Spectrophotometric 405 nm	Spectrophotometric 405 nm

Summary of Clinical Testing:

Two hundred and sixty sera from normal blood donors were assayed for the presence of Rubella IgG antibodies, using the SeraQuest™ Rubella IgG test and the INCSTAR Rubella IgG Clin-'SA™ test. Two hundred and four specimens were positive and forty-one specimens were yative in both tests. Seven specimens were negative in the SeraQuest Rubella IgG test, which were weakly positive in the INCSTAR Rubella IgG Clin-ELISA™ test; and 8 specimens gave equivocal results in the SeraQuest test, which were also weakly positive in the INCSTAR test. The latter test does not have an equivocal interpretation. Excluding the equivocal results, the overall agreement between the two tests was 97.2 % (95% Confidence Interval = 95.2 to 99.3). These results are shown below in Table 1.

TABLE 1.

RESULTS OF SeraQuest™ RUBELLA IgG ASSAYS, AND INCSTAR RUBELLA IgG Clin-ELISA ASSAYS, OF 260 SERUM SPECIMENS.

INCSTARRUBELLA IgG	SeraQuest RUBELLA IgG			95 % CI*
	Positive	Equivocal	Negative
Positive	204	8	7	Relative sensitivity	94.3 to 99.1
Negative	0	0	41	Relative specificityOverall agreement	95.4 to 10095.2 to 99.3

ixcluding equivocal results.

Calculated by the normal method .

Regulation Number and Section

§ 866.3510 Rubella virus serological reagents.

(a)
Identification. Rubella virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to rubella virus in serum. The identification aids in the diagnosis of rubella (German measles) or confirmation of a person's immune status from past infections or immunizations and provides epidemiological information on German measles. Newborns infected in the uterus with rubella virus may be born with multiple congenital defects (rubella syndrome).(b)
Classification. Class II. The special controls for this device are:(1) National Committee for Clinical Laboratory Standards':
(i) 1/LA6 “Detection and Quantitation of Rubella IgG Antibody: Evaluation and Performance Criteria for Multiple Component Test Products, Speciment Handling, and Use of the Test Products in the Clinical Laboratory, October 1997,”
(ii) 1/LA18 “Specifications for Immunological Testing for Infectious Diseases, December 1994,”
(iii) D13 “Agglutination Characteristics, Methodology, Limitations, and Clinical Validation, October 1993,”
(iv) EP5 “Evaluation of Precision Performance of Clinical Chemistry Devices, February 1999,” and
(v) EP10 “Preliminary Evaluation of the Linearity of Quantitive Clinical Laboratory Methods, May 1998,”
(2) Centers for Disease Control's:
(i) Low Titer Rubella Standard,
(ii) Reference Panel of Well Characterized Rubella Sera, and
(3) World Health Organization's International Rubella Standard.