What is a "foreign expert"?

[CCF Beijing]

I think we could learn alot from each other.

Those who would like to could expand their job descriptions and tell us a little bit more about their particular area (or areas) of expertise.

 

For example, after reading the database I am curious about:

 

• Hemoparasite Biochemistry
• Western Blot
• ELISA
• "ERP implementations"

 

J

[Jack Field]

Good idea. Maybe you might want to contact each person individually, hemoparasite biochemistry, wt....f, haha.

[Richard Roman]

Good point Jeff. Initially we want the basic info and then a more extended bio. Hopefully, over the next few months we will be developing this.

[José Félix Rojas Cabeza (罗哈斯)]

About Hemoparasite Biochemistry, it is about research on parasites that live in the blood (like Trypanosoma [causes sleeping sickness, Chagas' disease, etc] , leishmania [causes skin lesions] , and Plasmodium [causes Malaria]) using biochemical techniques. This parasites are very common in tropical countries (they infect mostly cattle and in some cases humans). 

Now my 2 cents about ELISA/WB. Elisa is a protein chemistry technique that is used to diagnose diseases (it stands for Enzyme Linked ImmunoSorbent Assay). The most familiar ELISA I can think of is a pregnancy test. If a girl is pregnant, she will produce a very specific protein which can be recognized by the adequate system. Below it's the detailed explanation of the test.

It uses 2 antibodies (one of which is coupled to an enzyme that has a well described activity), to determine whether a specific component is present in the sample. The basic Idea is that one antibody has 6 "fingers" which can "grab" very specific targets. The 2nd antibody's "hand" (or hypervariable region for those well versed in immunology) targets the 1st antibodies' constant region (FC). The test is made in small plastic wells (about 100 ul volume), you place the sample and use a specific buffer to adhere the proteins to the plastic (this phase is about 15mins), then empty the wells (there will be a lot of proteins that were in the sample present in the wells after emptying). After that you add the 1st antibody (in an apropriate dilution), let it rest for ~35m, then empty the wells. Posteriorly you add the 2nd antibody, then wait and discard the liquid again.

As I said, the 2nd antibody has attached (this would be a recombinant protein) an enzyme like alkaline phosphatase. Placing the appropriate reagents there will be a color change if the 2nd antibody is there. Thus it is possible to know if somebody has a specific virus/parasite or protein (like the corion protein specific to pregnant women) and you can decide if (S)he has a diesease (or clinical condition) or not. 

The Graphical representation would be like: |: well wall, -< : Antibody 1, =< antibody2 (remember this has an enzyme) and * would be the target (we want to know if this is present or not in the solution).

This would be the final stage of a positive (+) ELISA or WB.

|*>->=    

(you can check http://drugline.org/img/ail/1508_1519_1.jpg if my representation seems too crappy :P)

Remember this is in liquid and if we add the substrate to the enzyme on >= there will be a reaction that will produce color. 

In the negative case, there will not be anything attached to the well, because the "hand" of the first antibody failed to grab the target in the 2nd step, and everything was discarded, including the protein that would produce the color change.

Western blot is the same as ELISA, but the medium of the experiment is a nitrocellulose membrane (a plastic sheet), and the volume required for the experiment is about 5-10ml instead of 60ul... this is less exact and it's normally used for animal diagnosis since it's cheaper (it requires different reagents that are way less costly)