About Complement C3a R
C3a is an anaphylatoxin released during activation of the complement system. The protein encoded by this gene is an orphan G protein-coupled receptor for C3a. Binding of C3a by the encoded receptor activates chemotaxis, granule enzyme release, superoxide anion production, and bacterial opsonization. [provided by RefSeq, May 2016]

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.