A one step sandwich enzyme immunoassay for gamma-carboxylated osteocalcin using monoclonal antibodies.
A highly sensitive, simple and reliable one-step sandwich enzyme immunoassay (EIA) for the gamma-carboxylated form of osteocalcin (Gla-OC) has been developed using a monoclonal antibody. The minimum amount of Gla-OC detected by this EIA was approximately 0.2 ng/ml when a 10 microliter aliquot of the sample was used. The serum Gla-OC level in 30 healthy subjects was 3.6 +/- 2.19 ng/ml (mean +/- SD). A significant increase was seen in patients with chronic renal failure (20.3 +/- 4.60 ng/ml), atherosclerosis (8.3 +/- 4.94 ng/ml) and osteoporosis (10.1 +/- 4.60 ng/ml). The correlation between the values obtained by the sandwich EIA and competitive RIA methods was given by the linear regression equation, y = 2.896 + 0.759 chi, for which the correlation coefficient (r) was 0.815 (n = 58). This newly developed Gla-OC specific EIA may be useful for the diagnosis of metabolic bone disease and ectopic calcification.
Koyama
N
N
Biotechnology Research Laboratory, Takara Shuzo Co. Ltd., Shiga, Japan.
Ohara
K
K
Yokota
H
H
Kurome
T
T
Katayama
M
M
Hino
F
F
Kato
I
I
Akai
T
T
D000818:Animals; D000911:Antibodies, Monoclonal; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D015675:Osteocalcin / Q000032:analysis*; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D015675:Osteocalcin