Human Fibroblast growth factor receptor 1 (FGFR1), also known as BFGFR, CD331, CEK and FLT2, GenBank Accession No. NM_0023110.3, a.a. 399-822(end), with C-terminal Avi-His-tag, co-expressed with PTP1B for dephosphorylation in an Sf9 cell expression system and enzymatically biotinylated using Avi-tag™ technology. Biotinylation is confirmed to be ≥90% and phosphorylation is ≤5%. MW=51 kDa.