About PENK
This gene encodes a preproprotein that is proteolytically processed to generate multiple protein products. These products include the pentapeptide opioids Met-enkephalin and Leu-enkephalin, which are stored in synaptic vesicles, then released into the synapse where they bind to mu- and delta-opioid receptors to modulate the perception of pain. Other non-opioid cleavage products may function in distinct biological activities. [provided by RefSeq, Jul 2015]

About FITC
Fluorescein isothiocyanate (FITC) has an excitation peak at 495 nm and an emission peak at 519 nm. The name FITC is a misnomer in that the isothiocyanate is a reactive form of this dye. Once FITC is conjugated to an antibody, it is simply Fluorescein conjugated. FITC is one of the most widely used dyes for fluorescent applications, therefore most instruments come standard with a 488 nm laser and FITC filter set up. FITC is commonly conjugated to secondary antibodies and used in applications such as flow cytometry, immunocytochemistry, and immunohistochemistry. FITC is relatively dim, sensitive to photobleaching and it is susceptible to changes is pH. There are better performing alternatives to FITC, like Vio®Bright 515, Alexa Fluor™ 488, iFluor® 488, CF®488A and DY-488. FITC is a long-time generic dye with no sole manufacturer or trademark.