About Fos
The Fos gene family consists of 4 members: FOS, FOSB, FOSL1, and FOSL2. These genes encode leucine zipper proteins that can dimerize with proteins of the JUN family, thereby forming the transcription factor complex AP-1. As such, the FOS proteins have been implicated as regulators of cell proliferation, differentiation, and transformation. In some cases, expression of the FOS gene has also been associated with apoptotic cell death. [provided by RefSeq, Jul 2008]

About PE
Phycoerythrin (PE, R-PE) is a red-emitting fluorescent protein-chromophore complex that can be excited the 488-nm blue, 532-nm green, or 561-nm yellow-green laser with increasing efficiency and captured with a 586/14 nm bandpass filter. PE has an excitation peak at 565 nm and an emission peak at 578 nm. PE is 240kD in size and has an extinction coefficient of ~2x10^6 which makes it one of the brightest fluorophores available and a potent donor upon which to build tandem fluorophores with longer Stoke's Shifts.