3 you are running an elisa to determine whether your patient...

3. You are running an ELISA to determine whether your patient has been infected by HIV. a. Which of your patient’s fluids/tissues are you testing? b. What does an ELISA detect in your patient’s fluids/ tissues that allows you to determine whether your patient is HIV positive or HIV negative? c. What is the function of doing a serial dilution of your patient’s fluids in the ELISA listed above?

Transcript

00:06 Elisa stands for enzyme -linked immunosorbent acid.

00:12 Basically it uses the concept of specific antigen will be recognized by a unique antibody characteristics.

00:29 So it says that what basic principle of antibody -mediated immunity are utilized in elisa assay.

00:42 So for the basic concept is that antibody, i would say, produced by b cells, which is the mu cells, will recognize a unique antigen according to the cell surface, according to the antigen structure.

01:30 Structure.

01:36 And usually the antibody has a highly variable light chain.

01:41 So you can see that the antibody looks like a y -shaped protein.

01:46 So these two arms look like a light chain.

01:49 They are responsible for recognizing the antigen.

01:52 And the heavy chain is a constant region.

01:55 So as you can see, i put this y -shaped arm towards the antigen.

02:02 So the light chain, highly highly variable region of antibody will recognize a specific, very unique antigen.

02:09 So this is the basic concept of elisa.

02:13 The second question, how does the elisa indirectly detect infection by a disease -causing antigen? so usually the elisa is being carried out in a well.

02:31 So now inside of the the well, first of all, a primary antibody is being fixed.

02:40 And then the sample are being applied.

02:42 The sample may or may not contain the antigen.

02:49 If there's antigen, let's say this red circle is antigen, you will also incubate this well with, again, the primary antibody again.

03:04 The primary antibody will be recognized by a secondary antibody with a probe.

03:14 This probe usually causes a color change we call chromogen.

03:22 So you can see the first antibody is being immobilized on the bottom of the plate.

03:28 Then antigen binds to the antibody, and then primary antibody, the black one, binds to the antigen.

03:33 The secondary antibody binds to the primary antibody by the heavy chain.

03:41 And the secondary antibody has a chromogen.

03:44 So then the chromogen will characterize a reaction a chemical reaction cause color change.

03:53 So you can see if the antigen is present, the antigen is going to recruit the primary antibody, then secondary antibody.

04:04 The chromogen is an enzyme that will catalyze a chemical reaction cause color change.

04:09 So if you see a color change, you know the antigen is present...

Question

Please give Ace some feedback