This report describes an efficient strategy for amplified functional purification of the human H1 receptor after heterologous expression in Sf9 cells. The cDNA encoding a C-terminally histidine-tagged (10xHis) human histamineH1 receptor was used to generate recombinant baculovirus in a Spodoptera frugiperda-derived cell line (IPLB-Sf9). As judged from its ligand affinity profile, functional receptor could be expressed at high levels (30–40 pmol per 10 6 cells).