Measles Virus IgG Antibody Detection Kit (ELISA)

Instructions for the Measles Virus IgG Antibody Detection Kit (ELISA)
[Product Name]
Generic Name: Measles Virus IgG Antibody Detection Kit (ELISA)
[Packaging Specifications]
48 servings per box, 96 servings per box.
[Intended Use]
This product is intended for the in vitro qualitative detection of measles virus IgG antibodies in human serum or plasma samples.
Measles is an acute viral infectious disease caused by the measles virus (MV), characterized by fever, catarrhal symptoms of the respiratory tract, and a generalized maculopapular rash. Humans are universally susceptible to the measles virus. Transmission occurs directly via droplets from coughing or sneezing, or through contact with contaminated surfaces. The incubation period ranges from 9 to 11 days (up to 3 weeks in adults), followed by prodromal symptoms such as fever, cough, rhinitis, and conjunctivitis, which typically last 3–4 days. Fever intensifies within 24 hours. A rash appears on days 4–5 after the prodromal phase, marking the peak of symptoms. Simple measles rarely results in death; however, complications are a major cause of mortality. The most significant complications include bronchopneumonia, otitis media, encephalitis, and enteritis, with bronchopneumonia accounting for approximately 95% of measles-related deaths. Currently, the main clinical and laboratory diagnostic methods include hemagglutination inhibition (HI) assay, indirect hemagglutination assay (PHA), gel precipitation test, and enzyme-linked immunosorbent assay (ELISA); among these, ELISA reagents are widely used in clinical practice.
[Principle of Assay]
Principle of the indirect ELISA: A microtiter plate is coated with measles virus antigen. The serum or plasma to be tested is added to the wells, where any measles virus‑specific IgG antibodies present in the sample bind selectively 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 a microplate reader, allowing for the qualitative detection of measles virus‑specific IgG antibodies in the test sample.
[Main Ingredients]
1. The components included in this kit are:
No. Component Name Main Ingredient Usage Method Package Size
96 servings per box / 48 servings per box
1. Microtiter plate pre-coated with measles virus antigen: The microtiter plate is pre-coated with measles virus antigen derived from cultured, native virus. 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: horseradish peroxidase (HRP)-labeled anti-human IgG monoclonal antibody (mouse-derived); borate buffer containing 0.1% Proclin‑300, 0.002% phenol red, and a protein stabilizer. Ready to use. 6.5 mL × 1 vial; 3.5 mL × 1 vial.
3 Measles Virus IgG Antibody Positive Control: Human serum or plasma positive for measles 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 Measles virus IgG antibody negative control: borate buffer containing bovine serum albumin. For direct use. 1.0 mL × 1 vial, 1.0 mL × 1 vial.
5 Measles Virus IgG Antibody Critical Control: Positive human serum or plasma for measles 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: Borate buffer containing bovine serum albumin. For direct 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 conjugate, positive control, negative control, and cut-off control must be used exclusively from the kit supplied; products from other batch numbers are not permitted. Chromogen A, chromogen B, stop solution, and concentrated wash solution are universal reagents and may be used with all ELISA kits manufactured by this company.
2. Materials required but not yet provided:
A microplate reader with wavelengths of 450 nm and 630 nm.
Microplate washer
5 μL–40 μL, 40 μL–200 μL, and 200 μL–1 mL pipettes
37°C constant-temperature equipment
Micro-pore oscillator
[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 stored in a sealed bag at 2°C to 8°C. All components, once opened, should be used within one month.
See the label for the production date and expiration date.
[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. For plasma, anticoagulated plasma is recommended using EDTA‑K2 (1.5 mg/mL), sodium citrate (3.2 mg/mL), sodium oxalate (0.01 mol/L), or sodium heparin (12.5 IU/mL). Samples stored at room temperature should not exceed 8 hours; if testing is performed after 8 hours, the samples must be kept at 2°C–8°C. If storage exceeds one week, maintain samples at −20°C or lower and avoid repeated freeze–thaw cycles. Although endogenous substances below certain concentrations—bilirubin, hemoglobin, and triglycerides—do not significantly interfere with the assay results, samples exhibiting jaundice, hemolysis, or hyperlipidemia should still be avoided. Clearly contaminated samples are unsuitable for testing.
[Testing Method]
1. Precautions During the Experiment
1.1 When removing the kit components from refrigeration, allow them to equilibrate at room temperature (20°C–25°C) until no condensation is present 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 adding samples to the first well and the last well is too long, it will result in varying “pre-incubation” times, thereby compromising the accuracy and reproducibility of the measurements.
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 1:101 dilution: Take 5 mL of the sample to be tested and add it to a small test tube containing 0.5 mL of sample diluent, then mix thoroughly.
3. Testing Procedure
3.1 For each assay, include one blank well per plate (no blank well is required when using dual-wavelength detection), one positive control well, one negative control well, and three critical‑control wells. The blank well should contain only wash solution, developing reagent A, developing reagent B, and stop solution; the positive, negative, and critical‑control wells should be used directly at 100 µL per well. Add 100 µL of the diluted sample to all other 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 in the dark at 37°C ± 1°C for 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: Set the microplate reader to a primary wavelength of 450 nm and a reference wavelength of 630 nm, then measure the absorbance (A).
4. Reference Range
The negative control A-value is <0.10, the average A-value of the cutoff control is ≥0.20, and the positive control A-value is ≥0.80.
If the above conditions are met, the experiment is considered valid; otherwise, the results are invalid and the experiment must be repeated.
5. Result Interpretation
Calculate the S/CO value as follows: S/CO = Sample A value / Average 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]
If the IgG antibody test is negative, it indicates that the individual has not been infected or has not been successfully vaccinated. If the individual has not experienced an acute measles virus infection yet the IgG antibody test is positive, this suggests either a past infection or prior vaccination against measles.
[Limitations of the Analytical Method]
1. The test results of this product are intended for clinical reference only and should not be used as the sole basis for diagnosis or treatment. Clinical management of patients should be based on a comprehensive assessment that incorporates their symptoms/signs, medical history, epidemiological data, and other laboratory tests (such as pathogen‑specific assays).
2. In patients with compromised immune function or those undergoing immunosuppressive therapy—such as individuals infected with the human immunodeficiency virus (HIV) or recipients of organ transplants receiving immunosuppression—the serological antibody assays and antibody avidity tests have limited clinical utility and may lead to misinterpretation.
3. Individuals who have received blood transfusions or other blood-derived products in recent months should be evaluated with caution when their test results are positive.
4. Heterophilic antibodies in human serum may bind to the Ig in the reagent and interfere with test results; individuals who frequently come into contact with animals or animal‑derived serum products should be alert to the possibility of abnormal interference.
5. Samples from patients who have received mouse monoclonal antibody therapy may contain human anti-mouse antibodies (HAMA). If the sample to be tested contains HAMA, it may compromise the accuracy of the assay results.
6. Sample or reagent contamination by microorganisms, as well as cross-contamination among reagents, may lead to erroneous results.
7. Experimental results indicate that this product exhibits no cross-reactivity with IgG‑positive sera from the pathogens listed in the cross‑reactivity panel; however, no experimental data are currently available regarding cross‑reactivity with other pathogens.
[Product Performance Specifications]
1. Sensitivity, specificity
This product was evaluated using 1,315 samples from diverse populations and, when compared with commercially available similar assays, demonstrated a sensitivity of 99.3% and a specificity of 99.3%.
2. Repeatability and inter-batch variation
The within-run coefficient of variation (CV, %) shall not exceed 15% (n = 10).
Using three different lot numbers of the assay kit to test the same low‑value repeatability reference material, the between‑lot coefficient of variation (CV, %) among the three lots did not exceed 30% (n = 30).
3. Limit of detection
Perform the assay using the limit-of-detection reference standard; the result shall not exceed 0.4 IU/mL.
4. Interference Test
4.1 Anticoagulants (EDTA–K2 at 1.5 mg/mL, sodium citrate at 3.2 mg/mL, sodium oxalate at 0.01 mol/L, and sodium heparin at 12.5 IU/mL) do not significantly interfere with the assay results of this product.
4.2 Endogenous substances at concentrations below certain thresholds (bilirubin 0.4 mg/mL, hemoglobin 10 mg/mL, triglycerides 20 mg/mL), as well as antinuclear antibodies and rheumatoid factor, do not significantly interfere with the assay results of this product.
4.3 Fibrinogen does not significantly interfere with the assay results of this product; therefore, human serum or plasma samples may be used for testing.
4.4 This product shows no cross-reactivity with rubella virus IgG antibodies, mumps virus IgG antibodies, diphtheria IgG antibodies, pertussis IgG antibodies, tetanus IgG antibodies, hepatitis B surface antibodies, Japanese encephalitis virus IgG antibodies, hepatitis A virus IgG antibodies, meningococcal IgG antibodies, coxsackievirus IgG antibodies, respiratory syncytial virus IgG antibodies, Mycoplasma pneumoniae, adenovirus IgG antibodies, or Epstein–Barr virus IgG antibodies.
5. Hook Effect
This product exhibits no hook effect.
[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, positive, and critical controls 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 is impossible to guarantee the absence of all potential infectious agents in each component, this kit should be handled as potentially infectious material, and all personnel who come into contact with it must follow standard laboratory procedures.
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. The chromogenic solution contains TMB, and the stop solution contains sulfuric acid. Reagents containing TMB may trigger unintended reactions during the assay, while those containing sulfuric acid are corrosive. If these liquids come into contact with skin or mucous membranes, 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] Beckford AP, Kaschula RO, Stephen C. Factors associated with fatal cases of measles: a retrospective autopsy study. S Afr Med J, 1985, 68:858~863.
[Basic Information]
Registrant/Manufacturer Name: Zhuhai Special Economic Zone Haitai Biopharmaceutical Co., Ltd.
Address: No. 18, Innovation Fourth Road, Gangwan Avenue, Tangjiawan Town, Zhuhai City
Contact Information: Phone Number: 0756-3890858
Fax number: 0756-3890848
Name of After-Sales Service Provider: Zhuhai Haitai Biopharmaceutical Co., Ltd.
Contact Information: Phone Number: 0756-3890858
Production Address: No. 18, Innovation Road 4, Gangwan Avenue, Tangjiawan Town, Zhuhai City
Production License No.: Yue Shi Yao Jian Xi Sheng Chan Xu 20040941
[Medical Device Registration Certificate Number/Product Technical Requirement Number] National Medical Device Registration No. 20153401259
[Date of Approval and Date of Revision of the Instruction Manual] August 3, 2020