SERAQUEST RUBELLA IGG

K961053 · Quest Intl., Inc. · LFX · Sep 4, 1996 · Microbiology

Device Facts

• Record ID: K961053
• Device Name: SERAQUEST RUBELLA IGG
• Applicant: Quest Intl., Inc.
• Product Code: LFX · Microbiology
• Decision Date: Sep 4, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3510
• Device Class: Class 2

Intended Use

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 Story

SeraQuest Rubella IgG is a solid-phase enzyme immunoassay (EIA) for detecting IgG antibodies against rubella virus in human serum. The device uses rubella antigen-coated microwells; diluted patient serum is incubated, allowing rubella-specific IgG to bind. After washing, enzyme-labeled goat anti-human IgG conjugate is added, followed by an enzyme substrate. The substrate converts to a yellow end-product proportional to the amount of bound IgG, measured via spectrophotometry at 405 nm. The test is performed manually or using the HyPrep System Plus. Results are reported as Index values or IU/ml, traceable to WHO International Reference Preparation. Clinicians use these results to assess rubella infection status and patient immune response.

Clinical Evidence

Clinical study of 260 normal blood donor serum specimens compared SeraQuest Rubella IgG to the INCSTAR Rubella IgG Clin-ELISA. Results showed 204 positive and 41 negative concordant results. Excluding 8 equivocal results, overall agreement was 97.2% (95% CI: 95.2–99.3%). Relative sensitivity and specificity were high, with 95% CIs ranging from 94.3–99.1% and 95.4–100% respectively.

Technological Characteristics

Solid-phase enzyme immunoassay (EIA) using plastic microwells. Antigen strain: HPV 77. Detection system: Goat anti-human IgG conjugate with alkaline phosphatase enzyme and p-Nitrophenyl phosphate substrate. Readout: Spectrophotometric at 405 nm. Manual or automated (HyPrep System Plus) operation.

Indications for Use

Indicated for qualitative and quantitative detection of human IgG antibodies to Rubella in human serum to aid in determining rubella virus infection and assessing immunological response to rubella.

Regulatory Classification

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).

Special Controls

*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.

Predicate Devices

• Rubella IgG Clin-ELISA (INCSTAR Corporation)

Submission Summary (Full Text)

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APPENDIX 8.
Quest International, Inc., 1938 N.E. 148th Terrace, N. Miami, FL 33181
Page No. 254

# 510(k) SUMMARY

K961053

**Applicant:** Quest International, Inc.
1938 N.E. 148th Terrace
North Miami, FL 33181
**SEP - 4 1996**

**Registration No.** FDA form 2891 was submitted on April 1, 1995.

**Contact Person:** Robert A. Cort, President

**Telephone:** [phone]

**Telefax:** [phone]

**Manufacturing Site:** Same as above

**Device:** SeraQuest™ Rubella IgG

**Device Name:** Rubella serological reagents (21CFR § 866.3510)

**Device Classification:** Class III (premarket approval)

## 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.

## 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 draining, 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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APPENDIX 8.
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Page No. 255

## Extended Use:

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.

## 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 IgG antibodies against Rubella in human serum. | The detection of IgG antibodies against Rubella in 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 Incubation Duration: | 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 33181
Page No. 25

| Injugate Incubation Duration: | 30 minutes | 30 minutes |
| --- | --- | --- |
| Substrate: | p-Nitrophenyl phosphate | p-Nitrophenyl phosphate |
| Substrate 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 negative 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.

| INCSTAR
RUBELLA IgG | SeraQuest RUBELLA IgG | | | | |
| --- | --- | --- | --- | --- | --- |
| | Positive | Equivocal | Negative | 95 % CI* | |
| Positive | 204 | 8 | 7 | Relative sensitivity√ | 94.3 to 99.1 |
| Negative | 0 | 0 | 41 | Relative specificity√ | 95.4 to 100 |
| | | | | Overall agreement√ | 95.2 to 99.3 |

Excluding equivocal results.

Calculated by the normal method.