An improved latex agglutination-inhibition test for the detection of human chorionic gonadotropin in urine

A commercially available slide latex agglutination-inhibition test for pregnancy was used in a tube modification for the detection of human chorionic gonadotropin (hCG) in urine. The tube method used 100 microliters sample and small quantities of reagents which were mixed continuously for 30 min. The results obtained, based on flocculation, were 15-30-fold better than those obtained by slide agglutination using spiked samples or urine samples from pregnant women. The lowest concentration of hCG detected in the spiked samples was 31 IU/l. When 43 clinical specimens were examined, the tube method detected four more samples than the 18 detected by the slide method. A good correlation (r = 0.96) was observed between the two methods in the determination of the hCG content in the positive samples.