Preliminary Studies on Chemiluminescence Immunoassay for Human Chorionic Gonadotropin and Thyrotropin Using Acridinium Ester-Labeled Antibody

A highly sensitive chemiluminescence assay system for human chorionic gonadotropin (hCG) and thyroid stimulating hormone (TSH) was developed using a newly synthesized acridinium ester (AE) with a binding substitutional group at the N-10 position and having excellent chemiluminescence and stability. AE-labeled antibodies with an excellent chemiluminescence intensity were prepared after studying the labeling of anti-hCG antibodies with AE under different conditions. By studying the purification conditions for AE-labeled antibodies we produced AE-labeled antibodies having a low background value when assayed. When the detection limit is defined as the signal value+3SD at a concentration of zero for each substance measured, the detection limit for hCG is 0.01IU/l and that for TSH is 0.001μIU/ ml, demonstrating extremely high sensitivity. The labeled antibody′s stability is also excellent.