SIRP alpha protein, or Signal regulatory proteinalpha (SIRP-α), also known as Tyrosine protein phosphatase non-receptor type substrate 1, CD172a, Bit, and MyD-1, GenBank Accession No. NM_080792, a.a. 27-370, with C-terminal Avi and His tags, MW 40.3 kDa*, expressed in a HEK293 expression system and enzymatically biotinylated using Avi-tag™ technology. This SIRP alpha protein acts as a receptor for CD47; a.a. 27-370 correspond to the extracellular portion of SIRP-α. *Note: SIRP-α is heavily glycosylated, resulting in higher molecular weight.