IA-2 Autoantibody Human ELISA

Features

• RUO
• calibration range 7.5-4000 U/ml
• limit of detection 0.95 U/ml
• negative and positive control

Research topic

Autoimmunity, Diabetology - Autoimmunity

Summary

In BioVendor´s IA-2 Ab ELISA Version 2, IA-2 Ab in patients’ sera, calibrators and controls are allowed to interact with IA-2 coated onto ELISA plate wells. After a 16 – 20 hour incubation, the samples are discarded leaving IA-2 Ab bound to the IA-2 coated wells. IA-2-Biotin is added in a 2nd incubation step where, through the ability of IA-2 Ab to act divalently, a bridge is formed between the IA-2 immobilised on the plate and IA-2-Biotin. The amount of IA-2-Biotin is then determined in a third incubation step by the addition of streptavidin peroxidase (SA-POD) which binds specifically to Biotin. Excess, unbound SA-POD is then washed away and addition of the peroxidase substrate 3,3’,5,5’ – tetramethylbenzidine (TMB) results in formation of a blue colour. This reaction is stopped by addition of stop solution causing the well contents to turn from blue to yellow. The absorbance of the yellow reaction mixture at 405 nm and 450 nm is then read using an ELISA plate reader. A higher absorbance indicates the presence of IA-2 Ab in the test sample. Reading at 405 nm allows quantitation of high absorbances (and should be used for concentrations of 120 U/mL or more). It is recommended that low values (less than 35 u/mL) should be read off the 450 nm calibrator curve. If it is possible to read at only one wavelength 405 nm may be used. The measuring interval is 7.5 – 4000 U/mL (units are NIBSC 97/550).