What are monoclonal antibodies??

Gary C. Pien Gary_Pien at brown.edu
Thu Sep 28 00:33:29 EST 1995

Just to follow up on Peter Charles' response, monoclonal antibodies are a very 
powerful tool for cell studies when used in conjuction with flow cytometry. 
Basically, a flourescent molecule is attached to the antibody. This molecule will 
give off light of a particular wavelength when excited by a laser beam of a 
certain wavelength.

Now, if you have a mixed population of cells (say you grind up a spleen and 
now have a mixed suspension of splenocytes), and you want to identify a 
particular population, you can do so with the conjugated antibody. Find an 
antibody that will attach to a surface marker that is particular to only the type 
of cell you're looking for. Add some of this antibody to your mixed cell 
suspension; the antibodies will attach to the cells which have the antigen it 
recognizes. Now pass the mixture through a flow cytometer, which will 
basically sort droplets of your suspension into two buckets, one containing cells 
that flouresce, and one which contains cells that don't. Now, you've managed to 
separate out a specific population of cells from the entire mismosh you had 

This of course is overly simplistic, but you get the idea. With flow cytometry 
you can measure changes in populations of cells, percentage and raw number, 
the size or granularity of cells, and other interesting charateristics. In the case 
of the spleen I mentioned as an example, with flow cytometry you can track 
cellular changes in the spleen during the course of an infection.

Hope this helps,

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