Our newest instrument installed February, 2005, the Bio-Rad Bio-Plex flow cytometer, is specially designed to analyze microsphere based multiplex protein assays. This is an alternative to using ELISA assays to determine the concentration of proteins in solution, such as cell lysates. The advantage of doing multiplex assays is that one can get results simultaneously for many proteins dissolved in a very small volume.

Using the user friendly Bio-Plex software, standard curves of known concentration of all analytes are automatically computed and all data from the standards and unknowns can be displayed in graphic or table form. The results can also be saved in either form whichever is preferred by the investigator.

Kits for simultaneous quantitative measurement of up to 25-30 proteins are available. Examples of proteins that can be analyzed with commercially prepared Luminex microspheres are human/murine/rat cytokines, human/murine phosphoproteins, growth factors, kinases, and transcription factors. Users may also create custom assays for any proteins having corresponding antibodies.

Dual Excitation Sources:

1. A 10mW 532nm green diode used to excite the Phycoerythrin (PE)-strepavidin reporter molecule which is the indicator of protein binding to the individual beads.
2. A 10mW 635nm red diode use to excite the beads which emit 2 different wavelengths in varying proportions depending on the spectral address of the individual bead.

Helpful hints:

It takes several hours to set up the plates for the Bio-Plex, so it is helpful to start early in the morning. You may prepare your plates in room E-25 MSB if you do not have a vacuum manifold in your laboratory.