Catalog / ELISpot kits / IgM ELISpot kits

IgM ELISpot kits

We make ELISpot kits for IgM in 2 species. This page explains how they differ, so you can pick the one your experiment needs.

What differs between these kits

Which species they are for

Available for Human and Mouse. The species decides which antibody pair we supply, so it is the first thing to choose. Some kits are also validated on closely related species, so if you work in one we do not list here, check the reactivity on the product page.

Which detection system

Available with Streptavidin-ALP or Streptavidin-HRP. You add the streptavidin conjugate as a second incubation after the biotinylated antibody, which amplifies the signal. Alkaline phosphatase (ALP) and horseradish peroxidase (HRP) perform equivalently, so that choice usually comes down to the substrate and reader you already work with.

About IgM

Immunoglobulin M (IgM) is the first antibody isotype (also called class) secreted by the adaptive immune system in response to a foreign antigen. Plasma B cells secrete IgM mainly as pentamers, i.e., five IgM molecules joined together by the J chain. Because IgM is formed early in the immune response and is later replaced by IgG, specific antibodies of the IgM class are characteristic of a recent, ongoing, or chronic infection. Therefore, IgM represents the isotype with the lowest affinity for antigens. Due to its structure, with 10 antigen-binding sites per IgM pentamer, it can nevertheless bind surface-bound antigens with very high avidity. Immunoglobulin M constitutes approximately 10% of the total immunoglobulin concentration in serum. Resting mature yet naive, B lymphocytes express monomeric IgM as a transmembrane antigen receptor that functions as part of the B cell receptor (BCR).