Prevention of bridge binding in immunoassays: a general estradiol tracer structure.
Iodinated estradiol tracers were synthesized with three different bridges connecting the radiolabelled moiety to the steroid core: Hemisuccinate, carboxymethyloxime and amide. Taking these iodinated tracers in combination with ten antibodies raised against estradiol-6-CMO-albumin, titers and slopes of calibration curves have been compared to the corresponding data using a 3H tracer. The data indicate that the tracer with the amide bridge is recognized similarly to the tritiated estradiol by all antibodies tested, whereas the two other iodinated tracers exhibit substantial bridge binding. The results suggest that the amide tracer structure can generally be used to improve the quality of estradiol antibodies suffering from bridge binding effects.
Tiefenauer
L X
LX
Medical Bioanalytics Group Paul Scherrer Institute, Würenlingen, Switzerland.
Bodmer
D M
DM
Frei
W
W
Andres
R Y
RY
D000577:Amides; D000818:Animals; D000918:Antibody Specificity; D003429:Cross Reactions; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism; D007118:Immunoassay / Q000379:methods*; D007457:Iodine Radioisotopes; D007553:Isotope Labeling / Q000379:methods*; D013329:Structure-Activity Relationship; D014316:Tritium
D000577:Amides; D007457:Iodine Radioisotopes; D014316:Tritium; C002912:estradiol-6-(O-carboxymethyl)oxime; D004958:Estradiol; C016430:17 beta-estradiol hemisuccinate