A blotting matrix, in
molecular biology and
genetics, is the substrate onto which
macromolecules, such as
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
, are transferred in a
blot method.
The matrices are generally chemically modified paper filters or microporous membrane filters. In a
dot blot, macromolecules are applied directly to the matrix. Macromolecules can also be separated and transferred via
gel electrophoresis
Gel electrophoresis is a method for separation and analysis of biomacromolecules ( DNA, RNA, proteins, etc.) and their fragments, based on their size and charge. It is used in clinical chemistry to separate proteins by charge or size (IEF ...
.
One of the most common blotting matrices for protein analysis is
nitrocellulose, which has a high affinity for proteins due to hydrophobic interactions. However, proteins with low molecular weight have a small affinity for nitrocellulose, limiting potential applications. This defect may be remedied by
glutaraldehyde, which can covalently bond proteins to nitrocellulose. Another matrix is
cellulose paper modified with diazophenylthiother, which can also facilitate covalent bonding of proteins. Nylon membranes are also used for protein blotting, although they may result in the binding of anionic dyes such as
Coomassie blue and
Amido black
Amido black 10B is an amino acid staining azo dye used in biochemical research to stain for total protein on transferred membrane blots, such as the western blot. It is also used in criminal investigations to detect blood present with latent fi ...
.
Polyvinylidene fluoride membranes are also commonly used, due to their hydrophobicity.
References
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Molecular biology