Simple quantitative measurement of serum choriogonadotropin compared with immunoradiometric, immunoenzymometric, and chemiluminescent assays.

We evaluated a new simplified quantitative method (Tandem Icon QSR; Hybritech) for choriogonadotropin (hCG), which could theoretically be performed in a ward or with outpatients. The method was compared with immunoradiometric (Bioclone Australia), chemiluminescent (Amerlite; Amersham), and immunoenzymometric assays (Stratus; Dade). We analyzed by each of the methods 104 serum samples from pregnant and nonpregnant patients. For quantitative hCG values indicative of pregnancy (greater than 25 int. units/L), excellent correlation was observed between the Tandem Icon method and the other standard laboratory assays (r = 0.995, 0.990, and 0.992, respectively). Occasional problems arose because of the instability of Tandem Icon QSR reagents at room temperature but this was resolved by storing the reagents at 4 degrees C. We conclude that this simplified quantitative method for hCG is reliable and suitable for use outside of the routine immunoassay laboratory.