[Establishment of ELISA for measuring phenytoin in serum].
OBJECTIVE
To develop a solid phase, competitive enzyme immunoassay for the measurement of serum phenytoin.


METHODS
The chemical modified phenytoin combined with human serum albumin and then conjugated with horseradish peroxidase (HRP) to produce the enzyme labeled phenytoin (DPH-HSA-HRP). The anti-phenytoin antibody was prepared in this lab.


RESULTS
The working range and sensitivity of this method were 2.9-30 micrograms/ml and 2.87 micrograms/ml respectively. The intra-assay coefficient of variation (CV) was 3.3%-10.2% (n = 15) and inter-assay CV was 5.1%-13.2%. The recovery of this method was 90%-96%. No significant interference was observed with phenobarbital, primidone, carbamazepine, and valproic acid. The new assay method was compared with HPLC method. A linear regression analysis yielded a slope of 1.03, an intercept 1.38 and a correlation coefficient 0.97.


CONCLUSIONS
This solid phase enzyme immunoassay for serum phenytoin appears to be simple, precise, and accurate. It may be readily adopted in clinical laboratory for therapeutic monitoring of phenytoin level in serum.
Su
W
W
Clinical Laboratory, PUMC Hospital, CAMS, PUMC, Beijing 100730, China. suwei@csc.pumch.ac.cn
Lin
Q
Q
Song
Y
Y
D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D010672:Phenytoin / Q000097:blood*; D012680:Sensitivity and Specificity
D010672:Phenytoin