Development of a sensitive micro-magnetic chemiluminescence enzyme immunoassay for the determination of carcinoembryonic antigen.
A micro-magnetic chemiluminescence (CL) enzyme immunoassay with high sensitivity, selectivity, and reproducibility was developed for the determination of the tumor marker, carcinoembryonic antigen (CEA) in human serum. A sandwich scheme assay has been utilized with fluorescein isothiocyanate antibody (FITC)-labeled anti-CEA antibody and alkaline phosphate (ALP)-labeled anti-CEA antibody being used in the CL detection. The CL signal produced by the emission of photons from 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2'-adamantane) (AMPPD) was directly proportional to the amount of analyte present in a sample solution. The influences of the reaction time of antigen with antibody, the reaction time of substrate with label, the dilution ratio of ALP-labeled anti-CEA antibody, the concentration of FITC-labeled anti-CEA antibody, and other relevant variables upon the CL signal were examined and optimized. The CL responses depended linearly on the CEA concentration over the range from 2 to 162 ng mL-1 in a logarithmic plot. Assay sensitivity as low as 0.69 ng mL-1 was achieved. A coefficient of variance of less than 13% was obtained for intra- and inter-assay precision. This method has been successfully applied to the analysis of CEA in human serum. According to the procedure based on spiked standards, the recoveries obtained were 80-110%. Comparison experiments were carried out with the commercially available CEA chemiluminescence immunoassay. Satisfactory results were obtained according to a paired t-test method (t value<tcritical at the 95% confidence level).
Dungchai
Wijitar
W
The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
Siangproh
Weena
W
Lin
Jin-Ming
JM
Chailapakul
Orawon
O
Lin
Si
S
Ying
Xitang
X
D002138:Calibration; D002272:Carcinoembryonic Antigen / Q000097:blood* / Q000276:immunology; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007201:Indicator Dilution Techniques; D008163:Luminescent Measurements / Q000379:methods*; D008280:Magnetics; D012680:Sensitivity and Specificity; D013379:Substrate Specificity; D013997:Time Factors
D002272:Carcinoembryonic Antigen