Targets primarily the cell wall of Gram-positive organisms especially Staphylococcus aureus. Methicillin is used to study bacterium susceptibility, and to inhibit cell-wall synthesis. PBP's are enzymes which catalyze a pentaglycine crosslink between alanine and lysine residues providing additional strength to the cell wall. Without a pentaglycine crosslink, the integrity of the cell wall is severely compromised and ultimately leads to cell lysis and death. Methicillin Sodium Salt is inactivated by gastric acid so it is given to cells by other means in which gastric acid is not present in vitro.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.