How to Interpret an ELISA Test Result

ELISA elisa test result interpretation can be difficult to interpret if you don’t understand the basic principles behind the technology. Also known as enzyme-linked immunosorbent assay (EIA) or plate-based assay, an ELISA test detects soluble substances such as proteins and antibodies that are not easily detected with other methods like swab tests or Western blots. Medical professionals use ELISA to detect antigens like hormones or allergens and antibodies that the body has made in response to infection or vaccination such as those against HIV, hepatitis A, hepatitis B, and influenza.

During an ELISA experiment, the antibodies bind to antigens immobilized on an antibody-coated plate, resulting in a complex that is measured for activity by a reporter enzyme linked to the antibody. The detection system may utilize indirect, direct or chemiluminescent substrates. Often the sample is diluted to bring the analyte concentration into the detectable range of the assay. To correctly read a ELISA result, the concentration of an unknown sample can be determined by finding the point on the standard curve at which the absorbance signal matches the expected value, and then dividing this value by the average absorbance of the duplicate or triplicate readings for each standard and control.

ELISA Test Result Interpretation: How to Read and Understand Your Data

To get the most accurate results, always run ELISA in duplicate or triplicate and perform a trial-run using an empty plate and dilutions of the samples you are testing to get a feel for how the results should look before performing your actual assay. Also be sure to back up your data and keep a file of the raw and analyzed results in case they are needed for troubleshooting.