Measurement of human chorion gonadotropin by biological methods

The clinically significant biological activities of hCG result from its interaction with LH and TSH receptors. In vivo bioassays for measurement of these hCG activities have many disadvantages including complexity, expense, labor-intensity, and insensitivity. In vitro bioassays based on animal Leydig cell responses are widely used in research studies, but since they are based on animal receptors, their relevance to human biology remains uncertain. Visible on the horizon are in vitro bioassays constructed with human receptor genes transfected into cell systems by modern molecular techniques.