Ampicillin

Mode of Action

Inhibits the formation of cross-links in the peptidoglycan layer (which prvides rigidity to the cell wall). Most effctive against cells in log phase growth (since this is when new cross-links are being formed), and has little effect on cells in stationary phase.

Mechanism of Resistance

Expression of beta-lactamase neutralizes ampicillin. When this enzyme

References

Molecular Cloning: A Laboratory Manual, Vol 1.