Evaluation of a compact bench top immunoassay analyzer for automatic and near continuous monitoring of a sample for environmental contaminants.
A compact bench top immunoassay analyzer is evaluated and shown to possess sufficient automation to allow continuous unattended sampling and measuring while still achieving the theoretical (antibody affinity based) detection limit for analyte. The system is comprised of antigen coated particles in a disposable flow cell held at the focus of a filter fluorometer. Capture of fluorescently labeled antibody from the flow stream is inhibited by analyte in the sample, allowing analyte concentrations to be determined from the fluorescent intensity. The disposable cell was designed to allow easy end user changing of test specificity, e.g. for selection of any member of a panel of environmental contaminants. Standard curves are shown for six analytes of environmental interest, dioxin F114 (2,3,4,7,8-PeCDF), the pesticide Fenitrothion, three coplanar PCBs, including the most toxic, PCB 126, and estradiol. In each case the curves are constructed using antibody concentrations at or below the Kd of the antibody, assuring that the sensitivity shown is limited by the antibody itself rather than the analyzer. The dynamic range for the six analytes investigated ranged from a low of 5 to 340 pM for fenitrothion to a high of 0.8 to 59 nM for dioxin F114, and is correlated to the antibody Kd in every case. Data is also shown for 17 consecutive samples, including both high and low values, measured completely automatically over a period of hours. With further development and characterization, the bench top analyzer is expected to fill an important niche in environmental testing.
Glass
Thomas R
TR
Department of Bioscience, Central Research Institute of the Electric Power Industry, 1646 Abiko, Abiko City, Chiba 270-1194, Japan. tom@sapidyne.com
Saiki
Hiroshi
H
Joh
Takashi
T
Taemi
Yukihiro
Y
Ohmura
Naoya
N
Lackie
Steve J
SJ
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004147:Dioxins / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004958:Estradiol / Q000032:analysis*; D005278:Fenitrothion / Q000032:analysis*; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D016231:Fluorescence Polarization Immunoassay / Q000295:instrumentation* / Q000379:methods; D009862:Online Systems; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D015203:Reproducibility of Results; D012371:Robotics / Q000379:methods; D012680:Sensitivity and Specificity
D004147:Dioxins; D004785:Environmental Pollutants; D004958:Estradiol; D011078:Polychlorinated Biphenyls; D005278:Fenitrothion