Measles Virus IgM Antibody Detection Kit (Enzyme-Linked Immunosorbent Assay Capture Method)

Instruction Manual for the Measles Virus IgM Antibody Detection Kit (Enzyme-Linked Immunosorbent Assay Capture Method)
[Product Name]
Chinese Name: Measles Virus IgM Antibody Detection Kit (Enzyme-Linked Immunosorbent Assay Capture Method)
[Packaging Specifications]
48 servings per box, 96 servings per box.
[Intended Use]
Qualitative detection of measles virus IgM antibodies in human serum or plasma samples.
Used for the auxiliary diagnosis of measles virus infection.
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. Before the introduction of the measles vaccine, measles was globally distributed and was one of the leading infectious diseases threatening children’s health and lives.
Since China began administering the measles vaccine in 1965, and particularly following the launch of the Enhanced Immunization Program in 1984, the incidence of measles has declined sharply, with annual rates falling below 10 per 100,000. However, in recent years, as the mobile population has grown, some children have failed to receive adequate vaccination, leaving measles one of the most common viral infectious diseases among children. Annual incidence remains in the range of 50,000 to 100,000[1], and the true burden is likely higher than reported. Consequently, the country remains far from achieving the World Health Organization’s goals of measles control or elimination. Current vaccines do not provide lifelong protection[2], and measles is highly contagious, spreading primarily through respiratory droplets.
At present, China’s population exhibits high mobility, and when the susceptible population accumulates to a certain threshold, measles outbreaks and epidemics may occur. Moreover, due to the widespread use of the measles vaccine, opportunities for exposure to wild-type strains have diminished, leading to a gradual decline in antibody levels over time. This may ultimately result in an inability to fully protect against measles virus infection, manifesting as atypical clinical presentations [3]. Such atypical cases are often difficult to distinguish from rubella, human parvovirus B19, herpes simplex virus type 6, coxsackieviruses, echoviruses, and dengue virus infections. While typical measles can be diagnosed based on clinical features combined with epidemiological context, patients with atypical presentations require confirmation through serological testing for measles antibodies or isolation of the measles virus. Therefore, enhancing and refining laboratory diagnostic techniques for measles is crucial to ensure accurate and rapid diagnosis and timely monitoring of measles outbreaks.
[Principle of Assay]
Principle of the enzyme‑linked immunosorbent capture assay: A microtiter plate is coated with a monoclonal antibody against the human IgM μ chain. The serum or plasma to be tested is added to the wells, where any IgM antibodies present in the sample bind to the anti‑human IgM μ chain antibodies immobilized on the plate, forming an antibody–secondary antibody complex. After washing, a measles virus antigen conjugated to an enzyme is added, resulting in the formation of an (antibody–secondary antibody–enzyme‑conjugated antigen) immune complex. Following another wash, a chromogenic substrate is introduced; under the catalytic action of the enzyme, a colorimetric reaction develops. The intensity of this color reaction is measured using a microplate reader, allowing for the qualitative detection of measles virus‑specific IgM antibodies in the sample.
[Main Ingredients]
1. The components included in this kit are:
Serial No. Component Name Main Ingredient Usage Method Package Quantity
96 servings/box, 48 servings/box
1. Microplate pre-coated with anti-human IgM-μ chain antibody. The microplate is pre-coated with mouse monoclonal antibody against the human IgM-μ chain. Ready to use; can be separated into individual wells. Available in 96-well and 48-well formats.
2 Measles virus antigen–horseradish peroxidase (HRP) conjugate; borate buffer containing a preservative and a protein stabilizer. Ready to use. 6.5 mL × 1 vial, 3.5 mL × 1 vial.
3 Measles Virus IgM Antibody Positive Control: Human serum or plasma positive for measles virus IgM 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 IgM Antibody Negative Control: Human serum or plasma negative for measles virus IgM antibodies; borate buffer containing 0.02% thimerosal and a protein stabilizer. Ready-to-use. 1.8 mL × 1 vial. 1.8 mL × 1 vial.
5 Color-developing solution A: citric acid, hydrogen peroxide. Use directly 6.5 mL × 1 bottle 3.5 mL × 1 bottle
6 Color-developing solution B: citric acid, tetramethylbenzidine (TMB). Ready-to-use. 6.5 mL × 1 bottle, 3.5 mL × 1 bottle.
7 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
8 Sample Diluent (IgM) Borate buffer, containing glycerol. Ready-to-use 50 mL × 2 bottles 50 mL × 1 bottle
9 Stop solution: 0.5 mol/L sulfuric acid solution. Use directly: 6.5 mL × 1 bottle, 3.5 mL × 1 bottle.
10 zip-lock bags 1 piece 1 piece
11 Sealing films 4 pieces 4 pieces
12 Recording paper 1 copy 1 copy
Note: The enzyme conjugate, positive control, and negative control must be those provided with the kit; products from other batch numbers may not be used. The sample diluent (IgM) is compatible with our company’s ELISA kits for IgM 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
Micro-pore 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 plates should be stored in a sealed bag at 2°C to 8°C. Liquid components should be tightly capped and stored at 2°C to 8°C. All components must be used within one month of opening.
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 the clinical blood‑collection technical guidelines. Samples stored at room temperature should not exceed 8 hours; if testing is performed after 8 hours, samples must be kept at 2°C–8°C. For storage exceeding one week, maintain samples at –20°C or lower and avoid repeated freeze–thaw cycles. This assay is suitable for samples containing ethylenediaminetetraacetic acid (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 assay results, samples exhibiting jaundice, hemolysis, or hyperlipidemia should still 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, allow them to equilibrate at room temperature 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 conjugate, gently shake to ensure thorough mixing; prior to sample addition, use a microplate shaker to thoroughly mix the diluted samples.
1.5 Strictly adhere to the prescribed 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 all wells are free of wash buffer and to prevent foam formation. If using an automated plate washer, 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: Pipette 10 μL of the sample to be tested into a small test tube containing 1 mL of sample diluent (IgM), and mix thoroughly.
3. Testing Procedure
3.1 For each assay, include one blank well, one positive control well, and three negative control wells per plate. The blank well should contain no sample or enzyme conjugate; add only wash buffer, developing reagent A, developing reagent B, and stop solution. Use the positive and negative controls directly, 100 μL per well. Add 100 μL of diluted sample to all remaining wells. Incubate at 37°C for 60 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 for 60 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 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 Zero the instrument using a blank well, and read the absorbance (A) at 450 nm with a microplate reader; alternatively, calculate the A value using dual wavelengths (A450 nm – A630 nm).
4. Quality Control
The negative control value should fall between 0.0 and 0.15, and the positive control value should fall between 0.3 and 1.8; this confirms that the assay is valid. Otherwise, the results are invalid and the assay must be repeated.
[Positive Judgment Value]
If the mean A value of the negative control is less than 0.07, it shall be calculated as 0.07; if the mean A value of the negative control is equal to or greater than 0.07, it shall be calculated based on the actual value.
Calculate the S/N ratio; if the S/N ratio is ≥2.1, the result is considered positive. If the S/N ratio is <2.1, the result is considered negative.
S/N ratio = Sample A value ÷ Mean of negative control A values
[Interpretation of Test Results]
1. A positive result indicates acute or recent measles virus infection. For both positive and indeterminate results, it is recommended to collect a second sample for testing 1–2 weeks later to dynamically monitor changes in antibody levels.
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. The experimental results indicate that this product exhibits no cross-reactivity with IgM‑positive sera from the pathogens listed in the cross‑reactivity panel, nor with rheumatoid factor; however, no experimental data are currently available regarding cross‑reactivity with other potential interfering factors.

[Product Performance Specifications]
1. Sensitivity, specificity
In a clinical study involving 1,178 cases, this product demonstrated a sensitivity of 97.6% and a specificity of 89.0% when compared with a comparable imported reagent approved by the U.S. Food and Drug Administration (FDA).
2. Precision
The intra-assay coefficient of variation (CV%) shall not exceed 15% (n = 10).
3. Cross-reactivity
No cross-reactivity was observed between this product and IgM‑positive sera against rheumatoid factor or the following pathogens: Toxoplasma gondii, rubella virus, cytomegalovirus, herpes simplex virus type 1, and herpes simplex virus type 2.
4. Interference Test
4.1 Anticoagulants that come into contact with the sample (EDTA, sodium citrate, sodium heparin, sodium oxalate, and double oxalate) do not significantly interfere with the assay results of this product.
4.2 Fibrinogen does not significantly interfere with the assay results of this product; therefore, this product can be used to analyze human serum or plasma samples.
[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 and positive controls for this kit have been tested and found negative for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies, Treponema pallidum antibodies, and human immunodeficiency virus (HIV) antibodies. All other components of 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 treated as potentially infectious material, and all personnel handling 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 the 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] Wu Ting, Wang Shaoliang, Ling Luoya, et al. Strategies for Measles Control. Chinese Journal of Immunization Planning, 1998, 4:56–59.
[2] Xu Wenbo, Zhang Libi, Xia Tinghai, et al. Isolation of wild-type measles virus and preliminary serological analysis. Chinese Journal of Immunization Planning, 1996, 2(2):4–7.
[3] Martin DB, Weiner LB, Nieburg PI, et al. Atypical Measles in Adolescents and Young Adults. Ann Intern Med, 90:877–881.
[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
Contact Information: Phone Number: 0756-3890858
Fax number: 0756-3890848
Name of After-Sales Service Provider: Zhuhai Special Economic Zone 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 Food and Drug Administration Medical Device Production License No. 20040941
[Medical Device Registration Certificate Number/Product Technical Requirements Number] National Medical Device Registration No. 20163402560
[Date of Approval and Amendment of the Instruction Manual] December 29, 2016