of the four antibodies which were fully characterized , one recognized the intact hcg molecule only , a second recognized only the free beta-subunit , a third recognized only the free alpha-subunit and the fourth bound to the beta-subunit of hcg both when it was in the free form and when it was associated with the alpha-subunit forming the intact hcg molecule .
C0106132
beta-subunit
C0018062
hcg