The mecA gene is a gene found in bacterial cells. The mecA gene allows a bacterium to be resistant to antibiotics such as methicillin, penicillin, erythromycin, tetracycline and other penicillin-like antibiotics.The most commonly known carrier of the mecA gene is the bacterium known as MRSA. It is also found in Staphylococcus aureus and Streptococcus pneumoniae strains resistant to penicillin-like antibiotics. In Staphylococcus species, mecA is spread on the SCCmec genetic element.The mecA gene does not allow the ringlike structure of penicillin-like antibiotics to attack the enzymes that help form the cell wall of the bacterium (transpeptidases), and hence the bacteria is allowed to replicate as normal. The gene encodes the protein PBP2A (Penicillin binding protein 2A). PBP2A has a low affinity for beta-lactam antibiotics such as methicillin and penicillin. This enables transpeptidase[disambiguation needed] activity in the presence of beta-lactams, preventing them from inhibiting cell wall synthesis.

The antibody is stable for at least 1 year from the date of receipt when stored at -20°C to -70°C. Reconstituted antibody can also be aliquotted and stored at 4°C for 1 month or at -20°C to -70°C in a manual defrost freezer for many months without detectable loss activity. Please avoid freeze-thaw cycles.

This antibody binds to its immunogen, and did not show any cross reactivity with unrelated antigens in ELISA.