Hu Recom Prolactin, 50 µg

From STEMCELL Technologies, this preparation is an E. coli-expressed recombinant form of human prolactin (also known as luteotropin, luteotropic hormone, mammotropin, and PRL), a peptide hormone of pituitary origin well known for the initiation, maintenance, and stimulation of lactation as well as regulation of mammary gland development, immune function, metabolism, and behavioral modification. Its actions are mediated by the prolactin receptor (PRLR), a single-chain transmembrane protein. The protein carries UniProt accession P01236 and is provided as a lyophilized powder from a sterile-filtered aqueous solution containing sodium phosphate at pH 7.5.

Specifications include a predicted molecular mass of 23 kDa, purity of ≥ 95%, and an endotoxin level of ≤ 1 EU/μg protein as measured by kinetic limulus amebocyte lysate (LAL) analysis. Biological activity was determined using a Nb2-11 cell proliferation assay, with cell proliferation read after 66 hours by a fluorometric method; specific activity is ≥ 1 x 10^6 units/mg, corresponding to an EC50 ≤ 1 ng/mL, and the representative assay shown gives an EC50 of less than 0.02 ng/mL. Purity was confirmed by SDS-PAGE under reducing and non-reducing conditions with Coomassie Blue staining. Intended research uses highlighted by the manufacturer include work with human ES and iPS cell differentiation to pancreatic progenitors, culture of human mammospheres and tumorspheres, and studies of mouse and rat neural stem and progenitor cells.

For reconstitution, centrifuge the vial before opening and resuspend in sterile water containing 0.1% bovine serum albumin (BSA) to at least 0.1 mg/mL by pipetting down the sides of the vial; do not vortex, and omit BSA if the reconstituted product will be used immediately. The lyophilized material is stored at -20°C to -80°C and is stable for 12 months from the date of receipt. After reconstitution, store at 2-8°C for up to 1 month or at -20°C to -80°C for up to 3 months, avoiding repeated freeze-thaw cycles. For research use only; not intended for human or animal diagnostic or therapeutic applications.