Heptanoic acid is an organic compound composed of a seven-carbon chain terminating in a carboxylic acid. It is an oily liquid with an unpleasant rancid odor. It contributes to the odor of some rancid oils. It is slightly soluble in water but well soluble in ethanol and ether.

The Staphylococcus aureus transpeptidase Sortase A (SrtA) anchors virulence and colonization-associated surface proteins to the cell wall. SrtA selectively recognizes a C-terminal LPXTG motif. SrtA readily reacts with its native substrate Abz-LPETG-Dap(DNP)-NH2, cleaving it and catalyzing the formation of an amide bond between the carboxyl group of threonine and the amino group of cell-wall crossbridges.

Influenza Hemagglutinin (HA) Peptide is a tag peptide derived from an epitope of the influenza hemagglutinin protein.HA Peptide is a highly immunoreactive tag generally used for the separation of tagged proteins from cell culture supernatants and cell lysate under neutral pH conditions and thus are handy tools for coimmunoprecipitation but are also easily detected via western blot.