Re: multiplex

 Hi Rob.
As I understand it the term "multiplex" is used to describe the system where a particle
is identified by having different amounts of two (or more ) dyes. For example The Luminex
system uses two fluorescent dyes to identify beads which have an antibody on their
surface. This antibody will capture the soluble analyte for instance IL-2. Another
fluorescently labeled antibody to this same analyte is then added which will make the
bead fluoresce in this color also, the brightness  depending on the concentration of the
analyte. The Luminex system can  identify 100 different types of beads with different
reactivities using only two colors by combining various amounts of these two dyes, by
multiplexing. I'm sure there are some nice pictures on their web site. In flow cytometry
it seems to mean using two (or more) parameters to create many identifiable populations.
The word itself seems to have many uses. 


Simon Monard
Trudeau Institute
154 Algonqin Ave
Saranac Lake
New York
12983
Ph 518 891 3080


>>> "Robert J. Palmer Jr." <rjpalmer@dir.nidcr.nih.gov> 05/18/06 8:55 am >>> 
In my lab we are having a friendly discussion on the derivation and 
use of the term "multiplex".  What does this term mean and under what 
conditions is its use appropriate?  For example, does the use of 
FITC/TRITC/Cy5 qualify as a "multiplex" application?  If so, I would 
counter that this used to be called, appropriately, "multicolor" so I 
am not sure why replacement of that previously valid descriptor with 
the vague (?) term "multiplex" is desirable.  How about the use of 
several flavors of quantum dots?  This application seems to garner 
the modifier "multiplex" on a frequent basis.  When and how is this 
different than "multicolor"?
Thanks for the scientific lingo lesson :) :)!
Rob Palmer
--  
Robert J. Palmer Jr., Ph.D.
Natl Inst Dental Craniofacial Res -  Natl Insts Health
Oral Infection and Immunity Branch
Bldg 30, Room 310
30 Convent Drive
Bethesda MD 20892
ph 301- 594- 0025
fax 301- 402- 0396