Enzyme immunoassay for oxytocin.
A competitive, double antibody enzyme immunoassay for oxytocin in a heterologous system was developed. Horseradish peroxidase was conjugated with oxytocin using N-succinimidyl 3-(2-pyridyldithio) propionate, and rabbit anti-oxytocin serum was produced by immunization of oxytocin-bovine serum albumin complex which was prepared by the carbodiimide method. The sensitivity of the assay was 4 microIU/tube, which corresponded to 10 microIU per ml using 400 microliters of the sample which was extracted from the same volume of plasma by means of SEP-PAK C18 cartridges. The coefficients of variation for different levels of oxytocin ranged from 6.8-15.9% and 8.5-16.7%, for intra- and inter-assay. Recovery of oxytocin added to plasma after extraction was 99-117%. No or little cross-reaction with arginine- and lysine-vasopressin was found. Plasma oxytocin concentrations determined by the proposed enzyme immunoassay were well correlated with those determined by radioimmunoassay (r = 0.90).
Yasuda
T
T
Research & Development Div., Sumitomo Pharmaceuticals Co., Ltd., Osaka, Japan.
Mohri
Z
Z
Murakami
Y
Y
Takagi
T
T
Otsuki
Y
Y
Miyai
K
K
Tanizawa
O
O
D007124:Immunoenzyme Techniques; D010121:Oxytocin / Q000097:blood*; D011863:Radioimmunoassay
D010121:Oxytocin