What is ELISA?

Enzyme-Linked Immunosorbent Assay

Quick Answer

A widely used laboratory technique, ELISA stands for Enzyme-Linked Immunosorbent Assay. It detects and quantifies proteins, hormones, or antibodies in a sample, making it valuable in various scientific and medical fields.

Overview

ELISA is a laboratory method used to measure the presence of substances such as proteins, hormones, or antibodies in a sample. The process involves attaching an enzyme to an antibody that binds to the target substance. When a substrate is added, the enzyme reacts and produces a detectable signal, usually a color change, indicating the amount of the target in the sample. The technique works by first coating a plate with the target antigen or antibody. After adding the sample, any target substance will bind to the coated surface. Following this, a secondary antibody linked to an enzyme is introduced, which binds to the target. Finally, a substrate for the enzyme is added, leading to a measurable signal that correlates with the amount of target substance present. ELISA is important in many fields, including clinical diagnostics, where it can be used to test for diseases like HIV or to measure hormone levels in blood. For example, it can help in diagnosing allergies by detecting specific antibodies in a patient's blood. This method is preferred for its sensitivity, specificity, and ability to process many samples at once.

Frequently Asked Questions

What types of samples can be tested using ELISA?

ELISA can be used with various sample types, including blood, serum, plasma, and even urine. This versatility makes it applicable in many research and clinical settings.

How long does an ELISA test take?

The duration of an ELISA test can vary, but it typically takes a few hours to complete. This includes time for sample preparation, incubation, and analysis.

Is ELISA a quantitative or qualitative test?

ELISA can be both quantitative and qualitative, depending on how it is set up. It can measure the exact amount of a substance in a sample or simply indicate whether the substance is present.