title: AlphaLISA for the determination of median levels of the free β subunit of human chorionic gonadotropin in the serum of pregnant women.
abstract: Measurement of the free β subunit of human chorionic gonadotropin (free β-hCG) in serum is useful for prenatal screening. Concentrations of free β-hCG vary in different races. Conventional assays used for such measurements have limitations. We applied the AlphaLISA to measure levels of free β-hCG in maternal serum during 8-20 weeks of gestation in women from southern China. Two anti-free β-hCG antibodies were used: one was coated on AlphaLISA acceptor beads and the one was biotinylated. The assay also contained donor beads coated with streptavidin. The AlphaLISA assay detection limit was 0.11 ng/mL, and the analytical range was 0.11-200 ng/mL. The intra- and interassay coefficients of variation were 1.32%-2.50% and 3.44%-5.45%, respectively. The correlation with commercial Eu(3+)-labeled free β-HCG-TRFIA assay was good (y = 1.045x + 1.580, r(2) = 0.978). Median levels of free β-hCG in maternal serum at 8-20 weeks gestation were higher in women from southern China compared with those reported in women from other countries. The AlphaLISA for free β-HCG could become the assay of choice for applications in clinical diagnostics. The established median value of free β-HCG is helpful in clinical diagnosis specific for southern Chinese women.
authors.affiliation: Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zou
authors.forename: Tian-Cai
authors.initials: TC
authors.lastname: Liu
authors.forename: Guan-Feng
authors.initials: GF
authors.lastname: Lin
authors.forename: Zhi-Ning
authors.initials: ZN
authors.lastname: Dong
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Hou
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Ying-Song
authors.initials: YS
authors.lastname: Wu
mesh_terms: D000328:Adult; D044466:Asian People; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000592:standards*; D057230:Limit of Detection; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood* / Q000208:ethnology*; D011296:Prenatal Diagnosis
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human