Question

Which technique takes advantage of the fact that antibodies and antigens move toward one another on a plate coated with medium made from a natural polymer called agar?

Answer 1

The Ouchterlony assay, also known as double immunodiffusion, is a technique using agar gel to observe antibody and antigen movement and interactions, forming a visible precipitin arc.

Step-by-step explanation:

The technique that takes advantage of the movement between antibodies and antigens through an agar gel is known as the Ouchterlony assay or double immunodiffusion. This method, created by Orjan Ouchterlony in 1948, involves the use of agar, a natural polymer, to form a gel matrix in a plate. Holes are punched to create wells, where antibodies and antigens are placed, allowed to diffuse through the gel, and the point at which they meet forms a visible precipitin arc indicating a reaction.

This assay is a refinement of the precipitin ring test and overcomes some of its limitations, such as the need for large volumes of serum and the difficulty of avoiding mixing solutions. Moreover, the agglutination test, often conducted on cards or microtiter plates, also utilizes antibodies to identify serovars of bacteria and can detect the presence of antibodies or antigens in patient serum.