Rubella Virus IgG Antibody Detection Kit (ELISA)

Instructions for the Rubella Virus IgG Antibody Detection Kit (ELISA)
[Product Name]
Generic Name: Rubella Virus IgG Antibody Detection Kit (ELISA)
[Packaging Specifications]
48 servings per box, 96 servings per box.
[Intended Use]
This product is intended for the qualitative detection of rubella virus IgG antibodies in human serum or plasma.
Rubella virus belongs to the genus Rubivirus within the family Togaviridae. It is transmitted via the respiratory tract, with an incubation period of approximately 2 to 3 weeks. Following viral replication, it enters the bloodstream, leading to viremia. Clinical manifestations of rubella resemble those of a common cold: initial upper respiratory symptoms and enlargement of postauricular and suboccipital lymph nodes, followed by the appearance of pale pink maculopapular rash on the face that rapidly spreads throughout the body. In pregnant women, rubella infection may result in fetal death or congenital rubella syndrome (CRS).
Following rubella virus infection, specific IgM antibodies appear early, rise rapidly, and persist for a short duration, reaching their peak two weeks after the onset of rash and remaining detectable for 1–2 months. Detection of rubella virus–specific IgM antibodies is useful for diagnosing primary rubella infection. Rubella‑specific IgG antibodies emerge approximately one week after the appearance of IgM antibodies. IgG levels peak 4–6 weeks post‑infection, then gradually decline to a stable level that persists for life, serving as a long‑term marker of past infection. Testing for rubella virus–specific IgG antibodies can help determine whether an individual has had prior rubella infection and guide the implementation of appropriate measures—such as rubella vaccination—in susceptible populations.
[Principle of Assay]
Principle of the indirect ELISA: The microtiter plate is coated with rubella virus antigen. The serum or plasma to be tested is added to the wells, where any rubella virus–specific IgG antibodies present in the sample bind specifically to the antigen immobilized on the plate surface, forming an antigen–antibody immune complex. After washing to remove unbound material, an enzyme‑conjugated anti‑human IgG antibody is added, resulting in the formation of an (antigen–antibody–secondary antibody–enzyme conjugate) immune complex. Following another wash to eliminate excess bound reagents, a chromogenic substrate is added; under the catalytic action of the enzyme, a colorimetric reaction develops. The intensity of this color reaction is measured with an ELISA reader, allowing for the qualitative detection of rubella virus–specific IgG antibodies in the sample.
[Main Ingredients]
1. Components included in this kit
Serial Number Component Name Main Ingredient Usage Method Package Quantity
96 servings/box 48 servings/box
1. Microtiter plate pre-coated with rubella virus antigen: The microtiter plate is pre-coated with recombinant rubella virus antigen. It can be separated into individual wells for direct use, available in 96-well and 48-well formats.
2 Anti-human IgG antibody enzyme conjugate: mouse anti-human IgG antibody labeled with horseradish peroxidase (HRP); borate buffer containing a preservative and a protein stabilizer. Ready to use. 6.5 mL × 1 vial, 3.5 mL × 1 vial.
3 Rubella Virus IgG Antibody Positive Control: Human serum or plasma positive for rubella virus IgG antibodies; borate buffer containing 0.02% thimerosal and a protein stabilizer. For direct use. 1.0 mL × 1 vial, 1.0 mL × 1 vial.
4 Rubella Virus IgG Antibody Negative Control: Human serum or plasma negative for rubella virus IgG antibodies; borate buffer containing 0.02% thimerosal and a protein stabilizer. For direct use. 1.0 mL × 1 vial, 1.0 mL × 1 vial.
5 Rubella Virus IgG Antibody Critical Control: Positive human serum or plasma for rubella virus IgG antibodies; borate buffer containing 0.02% thimerosal and a protein stabilizer. For direct use. 1.8 mL × 1 vial, 1.8 mL × 1 vial.
6 Color-developing solution A: citric acid, hydrogen peroxide. Use directly. 6.5 mL × 1 bottle, 3.5 mL × 1 bottle.
7 Color-developing solution B: citric acid, tetramethylbenzidine (TMB). Ready to use. 6.5 mL × 1 bottle, 3.5 mL × 1 bottle.
8 Concentrated Detergent (10×) Phosphate-buffered solution, containing 0.5% Tween‑20, 10× concentrated. Dilute 10-fold with distilled or deionized water before use. 50 mL × 1 bottle 50 mL × 1 bottle
9 Sample Diluent (IgG) Borate buffer, containing glycerol. Ready to use 50 mL × 2 bottles 50 mL × 1 bottle
10 Stop solution: 0.5 mol/L H2SO4 solution. Use directly: 6.5 mL × 1 bottle, 3.5 mL × 1 bottle.
11 Sealed bags 1 piece 1 piece
12 sealing films, 4 pieces, 4 pieces
13 Recording Paper 1 copy 1 copy
Note: Enzyme conjugates, positive controls, negative controls, and cutoff controls must be those provided with the kit; products from other batch numbers may not be used. The sample diluent (IgG) is compatible with all of our ELISA kits for IgG antibody detection. Chromogen A, chromogen B, stop solution, and concentrated wash solution are universal reagents and can be used with all of our ELISA kits.
2. Materials required but not yet provided:
Distilled water or deionized water
Microplate washer
10 μL to 100 μL, 1 mL pipettes with disposable tips
37°C constant-temperature equipment
Microporous Oscillator
Microplate reader
A timer with a duration of 60 minutes or longer
[Storage Conditions and Shelf Life]
Store protected from light at 2°C to 8°C; shelf life is 12 months.
After opening, any unused microtiter plate should be placed in a sealed bag and stored at 2°C to 8°C. Each component, once opened, should be used within one month.
Production date and expiration date: See label for details.
[Applicable Instruments]
A microplate reader with wavelengths of 450 nm and 630 nm.
[Sample Requirements]
Serum or plasma samples should be collected in accordance with clinical blood‑collection guidelines. Samples stored at room temperature should not exceed 8 hours; if the assay is performed after 8 hours, store the samples at 2°C–8°C. For storage exceeding one week, maintain samples at −20°C and avoid repeated freeze–thaw cycles. This assay is suitable for samples containing EDTA, sodium citrate, sodium heparin, sodium oxalate, or double‑oxalate anticoagulants; however, there are currently no experimental data on the suitability of samples containing other types of anticoagulants. Although bilirubin, hemoglobin, and triglycerides do not significantly interfere with the kit’s results, samples exhibiting jaundice, hemolysis, or hyperlipidemia should be avoided. Clearly contaminated samples must not be used for testing.
[Testing Method]
1. Precautions During the Experiment
1.1 When the kit components are removed from refrigeration, they should be allowed to equilibrate at room temperature (20°C–25°C) until no condensation is visible before use. After opening, any unused microtiter plates should be stored in a sealed bag.
1.2 During storage and incubation, direct exposure to strong light should be avoided. All reagent vials must be tightly capped to prevent evaporation and contamination.
1.3 To prevent microbial contamination and cross-contamination of reagents or samples, disposable pipette tips should be used and not reused.
1.4 Before aliquoting the standard and enzyme‑labeled reagents, gently shake them to ensure thorough mixing; prior to sample addition, use a microplate shaker to thoroughly mix the diluted samples.
1.5 Strictly adhere to the specified incubation time and temperature. If the interval between sample addition in the first well and the last well is too long, it will result in varying “pre-incubation” times, thereby significantly affecting the accuracy and reproducibility of the measurement results.
1.6 At the end of the washing step, invert the microplate onto a paper towel and gently tap it to ensure that no residual wash solution remains in any well, thereby preventing foam formation. If an automated plate washer is used, be sure to operate it correctly.
2. Experimental Preparation
2.1 Preparation of Reagent Kit Reaction Reagents
2.1.1 Microporous Strip
Secure the required number of microplate strips to the plate holder, and store the remaining strips in a sealed bag.
2.1.2 Washing Solution
Dilute the concentrated detergent in a clean graduated cylinder. Add 50 mL of concentrated detergent to distilled or deionized water up to a final volume of 500 mL, and mix thoroughly.
2.1.3 Other Liquid Components
Use directly; shake gently before use to ensure thorough mixing.
2.2 Sample Preparation
Sample 1:100 dilution: Take 10 µL of the sample to be tested and add it to a small test tube containing 1 mL of sample diluent (IgG), then mix thoroughly.
3. Testing Procedure
3.1 For each assay, include one blank well (unless using dual-wavelength detection, in which case no blank well is required), one positive control well, one negative control well, and three critical‑control wells. The blank well should contain only wash buffer, developing reagent A, developing reagent B, and stop solution; do not add sample or enzyme conjugate. The positive, negative, and critical controls should be used directly at 100 μL per well. Add 100 μL of the diluted sample to all remaining wells. Incubate at 37°C ± 1°C for 30 minutes.
3.2 Discard the liquid from the wells, then add washing solution to each well until it is completely filled (approximately 300 μL per well). Remove the excess by tapping the plate gently and blotting dry, repeating this process three times. Except for the blank well, add 50 μL of enzyme‑labeled reagent to each well and incubate at 37°C ± 1°C for 30 minutes.
3.3 Discard the liquid from the wells, wash the plate three times as described above, and after blotting dry, add 50 μL of developing reagent A and 50 μL of developing reagent B to each well. Incubate at 37°C ± 1°C in the dark for 10–15 minutes, then add 50 μL of stop solution to each well and gently shake the microplate to ensure thorough mixing.
3.4 Single-wavelength detection: Zero the instrument using the blank well, then measure the absorbance (A) at 450 nm with a microplate reader.
Dual-wavelength detection: Read the absorbance values at 450 nm and 630 nm using a microplate reader, and calculate the net absorbance as A450nm – A630nm.
4. Reference Range
The negative control A-value shall be ≤0.15; the average A-value of the cut-off control shall be between 0.20 and 0.8, with an A-value ratio of cut-off control to negative control ≥2.0; and the positive control A-value shall exceed the average A-value of the cut-off control. Only under these conditions is the assay considered valid; otherwise, the results are invalid and the assay must be repeated.
[Positive Judgment Value]
Calculate the S/CO value as follows: S/CO = Sample A value / Mean of the critical control A values.
Reactivity (R): S/CO ≥ 1.1
Suspicious (S): 0.9 < S/CO < 1.1
Negative (N): S/CO ≤ 0.9
[Interpretation of Test Results]
1. A reactive result indicates either a past rubella virus infection or prior vaccination against rubella. For indeterminate results, repeat testing is recommended, or a second sample should be collected and tested after two weeks to monitor changes in antibody levels over time.
2. The test results are for clinical reference only; clinicians should integrate the patient’s medical history, symptoms, and other diagnostic findings to arrive at a diagnosis.
[Limitations of the Analytical Method]
1. Microbial contamination of samples or reagents, as well as cross-contamination between reagents, may lead to erroneous results.
2. This method detects rubella virus IgG antibodies and does not directly indicate the presence of rubella virus in the sample.
[Product Performance Specifications]
1. Sensitivity, specificity
This product was evaluated using 1,144 samples from diverse populations, demonstrating a sensitivity of 99.9% and a specificity of 99.8%.
2. Precision
The within-run coefficient of variation (CV, %) shall not exceed 15% (n = 10).
3. Interference Test
3.1 Anticoagulants that come into contact with the sample (EDTA, sodium citrate, sodium heparin, sodium oxalate, and double oxalate) do not significantly interfere with the test results of this product.
3.2 Endogenous substances—bilirubin, hemoglobin, and triglycerides—do not significantly interfere with the assay results of this product.
3.3 Fibrinogen does not significantly interfere with the assay results of this product; therefore, human serum or plasma samples may be used for testing.
[Precautions]
1. This product is intended for in vitro diagnostic use only and is for single-use.
2. The serum or plasma used to prepare the negative control, positive control, and cut-off control for this product have been tested negative for HBsAg, HCV antibodies, Treponema pallidum antibodies, and HIV antibodies, and all other components included in the kit are non‑infectious. However, since it cannot be guaranteed that all potential infectious agents have been detected in each component, this product should be treated as potentially infectious material, and all personnel handling the kit must follow laboratory safety protocols.
3. All clinical specimens shall be treated as infectious materials.
4. Samples awaiting testing and other potentially infectious materials shall be disinfected after testing.
5. Take care to avoid direct contact between the reagents or samples and skin or mucous membranes. Color development solution B contains TMB, which may trigger other reactions during the assay; the stop solution contains sulfuric acid and is corrosive. If these liquids come into contact with skin or eyes, rinse thoroughly with water immediately.
[Explanation of the Logo]
Packaging label
The logo
Meaning of the label: Temperature limit; In vitro diagnostic medical device; Refer to the instructions for use; Do not reuse.
[References]
[1] Geng Guanyi. Epidemiology (Volume 2). 2nd ed. Beijing: People’s Medical Publishing House, 1996. pp. 541–551.
[2] PaulD, ParkmanK. Making vaccination policy:the experience with rubella. Clin Infec Dis, 1999, 28:140~146.
[3] Xu Fugeng, Huang Chengxiao, Yao Huaifang, et al. Rubella antibody screening and immunization study among individuals aged 1–29 years in Hangzhou. Journal of Epidemiology, 1995, 16: 94–96.
[4] Dai Bin, Fang Hanhua, Han Xiujuan, et al. A study on the incidence of primary rubella infection in women during early pregnancy. Chinese Journal of Preventive Medicine, 1992, 269:197–199.
[5] RazkallaS, RaikarS, KlonerRA. Treatment of Viral Myocarditis with Focus on Captopril. [J]. Am J Cardiol, 1996, 77 (8), 634–636.
[Basic Information]
Registrant/Manufacturer Name: Zhuhai Special Economic Zone Haitai Biopharmaceutical Co., Ltd.
Address: No. 18, Innovation Road No. 4, Gangwan Avenue, Tangjiawan Town, Zhuhai City Postal Code: 519085
Contact Information: Telephone: 0756-3890858 Fax: 0756-3890848
Name of After-Sales Service Provider: Zhuhai Special Economic Zone Haitai Biopharmaceutical Co., Ltd.
Contact Information: Telephone: 0756-3890858 Fax: 0756-3890848
Production Address: No. 18, Innovation Road 4, Gangwan Avenue, Tangjiawan Town, Zhuhai City Postal Code: 519085
Production License No.: Yue Food and Drug Administration Medical Device Production License No. 20040941
[Medical Device Registration Certificate Number/Product Technical Requirements Number] National Medical Device Registration No. 20173400136
[Date of Approval and Amendment of the Instruction Manual] January 23, 2017