Sandwich ELISAs typically require the use of matched antibody pairs (capture and the detection antibody), where each antibody is specific for a different, epitope of the antigen molecule.
The capture antibody often is a monoclonal antibody as they only bind a single epitope on an antigen. This increases the specificity and reduces background noises as well. A polyclonal is often used as the capture antibody to pull down as much of the antigen as possible. Sandwich ELISA can be direct or indirect depending on whether the detection antibody is labeled or unlabeled. If an indirect detection method is chosen, special care must be taken to ensure that the secondary antibody used reacts only with the detection antibody and not with the capture antibody coated on the plate. The ELISA is suitable for complex samples, since the antigen does not require purification prior to measurement and offers 2-5 times enhanced sensitivity compared to (In)direct ELISA.Our support team will gladly help you with finding the right ELISA kit for your needs. Please contact us via phone, email or use our live chat system.