GeneMedi's protocol / procedure for the diagnostics application-Immunonephelometry
1 Immunonephelometry
antibodies in a sample by detecting the amount of light scattered by the immune complexes formed during the reaction.
The principle is based on the detection of changes in the scattering of light due to the formation of larger complexes as the antigen-antibody reaction proceeds.
In immunonephelometry, a sample containing the analyte of interest is mixed with a specific antibody conjugated to a colored latex particle.
The antigen-antibody complex is formed and the light scattered by the immune complex is measured with a photodetector placed at an angle of 90 degrees to the incident light source.
The amount of light scattered is proportional to the size and concentration of the immune complexes present in the reaction mixture. A calibration curve is generated using standard samples of known concentrations to determine the concentration of the analyte in the unknown sample.
1.1 Advantages
- High sensitivity and specificity for detecting low levels of antigens or antibodies
- Rapid and easy-to-use protocol with minimal sample preparation required
- High throughput capability, allowing for analysis of large numbers of samples in parallel
- No washing steps required, reducing the potential for human error and making it easier to automate
- Can be used to detect a wide range of analytes, including small molecules, proteins, and nucleic acids
1.2 Disadvantages
- May be affected by interference from other substances present in the sample, leading to false positive or negative results
- May not be suitable for measuring the affinity of antigen-antibody interactions, since the size of the immune complexes detected may not be directly proportional to the affinity of the interaction.
- Cannot distinguish between different isotypes or subtypes of antibodies
- Equipment and reagents required for immunonephelometry can be costly
1.3 Test Procedure/Protocol for Immunonephelometry
The specific test procedure for immunonephelometry may vary depending on the assay kit and target analyte. However, here is a general outline of the steps involved:
- Sample Collection and Preparation: Collect the specimen (e.g., serum or plasma) following appropriate techniques. If necessary, process the sample to remove interfering substances or concentrate the analyte.
- Reagent Preparation: Prepare the necessary reagents provided in the assay kit, such as buffers, calibrators, and controls, according to the manufacturer's instructions.
- Calibration Curve: Prepare a calibration curve using the provided standards with known concentrations of the analyte. This will help quantify the concentration of the analyte in the sample.
- Sample Incubation/reaction: Mix the sample with the appropriate antibodies react with the analytes in the samples and incubate for a specific period to allow the formation of immune complexes.
- Measurement of Light Scattering: Measure the intensity of light scattering caused by the immune complexes using a nephelometer. The intensity of the scattered light is proportional to the concentration of the analyte in the sample.
- Data Analysis: Compare the light scattering measurements of the sample with the calibration curve to determine the analyte concentration. Some assays may require additional calculations or data processing steps.
- Quality Control: Perform appropriate quality control measures to ensure the accuracy and reliability of the results, following the guidelines provided by the assay kit manufacturer.