using an antiserum ( h-93 ) specific to the cooh-terminal peptide of hcg beta and gel chromatography , we found the transitory ( 1-2 days ) presence of a gonadotropin having immunological , biological , and physical similarity to hcg , but not typical hlh , in the late luteal phase ( days 24-29 ) urine of some ( 5 of 26 ) iud users .
C0106132
hcg beta
C0018061
gonadotropin