Match the following serological tests in column A to the descriptions in column B.

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Video transcript

Hi, everybody. Let's take a look at the next problem. It says all of the following tests can detect the presence of antibodies except A Eliza B compliment fixation, C western blotting or D acid vst staining. So all these tests, the only one that does not involve antibodies in some way is choice d acid fast staining. So that's going to be our answer since we're looking for the one that cannot detect the presence of antibodies. Acid fast staining is a method of looking for specific types of bacteria called acid-fast bacteria, acid bacteria being the bacteria that are resistant to decol organization by acid alcohol. And why would you want to do this? Mainly because one of these bacteria is the bacteria that causes tuberculosis. So this is a way of testing for tuberculosis or other mycobacteria infection, but it does not detect the presence of antibodies. So it's going to be our answer. We'll just look briefly at our other answer. Choices to be thorough choice. A Eliza uh all capitals el isa is an acronym for enzyme linked immunosorbent assay. This is a very um easy to use a scalable process that can be easily scaled up to test large numbers of samples. It's carried out in trees with little wells and you have either an antigen or an antibody bound to the well. And then use binding of either an antibody or antigen to whatever is in the. Well, then you bind an enzyme which is why it's enzyme linked and have some way of detecting it whether using a dye or fluorescence that tells you about whether you have the antigen or antibody you're looking for. So you rinse those wells with a solution of the corresponding antibody or antigen depending on what you have bound and then you rinse with a labeled enzyme. So this does detect the presence of antibodies. So it's not our answer. Choice. B complement fixation uh is a similar idea that you're using the specificity of binding with an antibody. In this case, you are looking at complement proteins, complement proteins bind to an antigen antibody complex. So you can use that binding to detect small amounts of antibody if you use a labeled complement protein. So this can be used as a diagnostic test, but it's a very tricky process as compared to Eliza, which is much easier as well as being able to be uh scaled up. So this is not nearly as popular as the Eliza test, but again detects the presence of antibodies. So not our answer. And then finally choice C western blotting is used for the identification of for instance, a single protein in a mixture, you run a protein mix on a gel, transfer it to protein binding paper, then rinse with an enzyme length antibody. You can see where it binds. You can see a band identifying where the antibody has bound to the protein. But again, you use these labels, anti labeled antibodies that are binding to proteins. So you can see the presence of antibodies and therefore not the answer to the problem that we're looking for. So once again, the test that is an exception. The one test that does not detect the presence of antibodies among this group is choice d acid fast staining. See you in the next video.