ELISA Service

Enzyme-Linked ImmunoSorbant Assay (ELISA) is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. In simple terms, in an ELISA an unknown amount of antigen is affixed to a surface, and then a specific antibody is washed over the surface so that it can bind to the antigen. This antibody is linked to an enzyme, and in the final step a substance is added that the enzyme can convert to some detectable signal.

The success of a custom antibody project primarily depends on how immunogenic the peptide or protein is and the immunochemical technique used for evaluation. It is essential to know that each immunochemical technique presents the antigen in a distinct way. An antibody that works excellent for one technique (western blot for example) may not work well for another (IHC).

An ELISA is a simple method to assess whether an antibody response against the immunizing antigen has occurred. As the serum is diluted, the titer as determined by an ELISA service should continually decrease. Antibody is present when the ELISA titer is greater than or equal to 0.1, normalized against the pre-bleed. It is advantageous to have antibody at the highest possible dilution. For ELISA service, please note that titers will fluctuate over time, there are no predicable patterns. For example, a low ELISA titer may increase over time with additional boosts or it may not. Conversely, a high ELISA titer may be maintained over time, or it could decrease even with subsequent immunizations.

ProSci has performed thousands of ELISA assays to determine antibody titer. For analytical determinations using ELISA techniques, please contact us at abservices@prosci-inc.com, or call 1-888-513-9525.