What is Sandwich ELISA?
Sandwich ELISA (Enzyme-Linked Immunoassay also known as EIA) is a diagnostic technique used to find antigens or antibodies in biological samples. This technique is one of four types of microplate tests: Direct, Indirect, Sandwich, and competitive ELISA. Sandwich ELISA allows for the use of monoclonal versus polyclonal antibodies to capture antigens.
Should we use monoclonal or polyclonal antibodies as the primary antigen in Sandwich ELISA testing?
A question most often asked in technical forums. In this article, we take a look at this question, the advantages, and disadvantages of monoclonal versus polyclonal antibodies as primary or capture antigens.
Monoclonal Sandwich ELISA Antibodies
Monoclonal antibodies are single antibodies from producing B-cells, therefore it only binds with 1 unique epitome.
Technically speaking, individual antibodies in a polyclonal mix are monoclonal antibodies.
However, the terminology describes a process where the actual B-cell is isolated. Once isolated, the B-cell fuses into a hybrid cell line. This way, technicians produce large volumes of identical antibodies.
Monoclonal Antibody advantages
Monoclonal Antibody Disadvantages
Polyclonal Sandwich ELISA Antibodies
Polyclonal antibodies are manufactured from different B-cells, recognizing several antigenic determinants (epitope) on the same antigen. The epitope is unique to the antigen. Each antibody recognizes this unique epitope located on the specific antigen.
Polyclonal Antibody advantages
Polyclonal Antibody disadvantages
Should I use Monoclonal or Polyclonal antibodies as binding antibodies?
Firstly, decide on the type of test that you have to develop. Secondly, it will determine the type of antibodies you will need. Thirdly, ensure that the antibodies work for the specific test that you develop.
Practical tips when developing a test
About Marinda Stuiver
Dip, NHDip Microbiology (Vet) TUT (1989)
Marinda Stuiver is a qualified Veterinary Microbiologist with more than 12 years of laboratory experience.
Her experience includes histology, Electron Microscopy, and ELISA testing. Following the sale of the laboratory where she worked, she ventured into the commercial side of the business.
Marinda sold IDEXX ELISA test kits to various laboratories in Southern Africa (Zimbabwe, Botswana, Malawi) and trained laboratory staff to set up and conduct testing.