Research Paper

The Virtual Lab – ELISA Test

Lab:

Immunology

09/04/2013

Instructors:

Dr. Charlie Wilson

Written by:

Dipen Patel

I. Objective:

The purpose of the lab was to learn the procedure of performing an ELISA test to determine whether a particular antibody is present in a patient’s blood sample. ELISA is an abbreviation for “Enzyme-linked Immunosorbent Assay."

II. Introduction:

The interaction of antigen and antibody outside the body can be used to determine if patient has an infectious or an autoimmune disease. In this particular exercise, the sample blood is collected from three different patients. And after, separating the red blood cells and serum, a serum was used to perform the ELISA test.

a. ELISA Test

ELISA is an abbreviation for “Enzyme-linked Immunosorbent Assay." An ELISA test uses components of the immune system and chemicals to detect immune responses in the body, such as infectious microbes. The ELISA test involves an enzyme, antibody and antigen.

There are variations of the ELISA test, but the most basic type consist of an antibody attached to a solid surface. This antibody has affinity for the substance of interest, for example, human chorionic gonadotropin (HCG), the commonly measured protein which indicates pregnancy. In ELISA, the antigen-antibody complex is exposed to the second antibody, which binds to the antibody portion of the complex creating sandwich type structures. The signaling system consists of an enzyme attached to the second antibody. And, on adding of the appropriate chemical, an enzyme converts it to a colored substance, which can be quantified. And the test is qualified by the amount of color produced. The more enzyme present, the more secondary antibody must be present is determined by the amount of target, or the first antibody available. Finally, because the first antibody binds to antigen, the more antigen that is accessible, the more first antibody is retained. Therefore, the measure of color reflects the...