Ampicillin sodium salt
Ampicillin is a ß-lactam antibiotic that inhibits bacterial cell-wall synthesis by inactivating transpeptidases on the inner surface of the bacterial cell membrane. Ampicillin in solution is a function of pH, temperature and the identity of the buffer. It’s activity is quickly lost when stored above pH 7.
Ampicillin is usually used at a concentration of 50 - 100 µg/mL. Stock solution is typically at 25mg/mL
- According to desired amount of antibiotics, calculate the amount in grams that has to be weighed.
- For example, for 10mL of 25mg/mL of Ampicillin:
- Ampicillin is soluble in ddH2O.
- Filter sterilize solution using a 0.2 µm syringe filter.
- Divide in aliquots of 500μL
- Store at -20 °C. up to 4-6 months
"It is stable at 37°C for three days. Additional studies have shown that the stability of Ampicillin in solution is a function of pH, temperature and the identity of the buffer. It′s activity is quickly lost when stored above pH 7. " Sigma
For culture plates, allow media to cool to 55 °C before adding ampicillin to a final concentration of 35-50 μg/ml.
For Example, for 300 mL of media at a final concentration of 50µg/mL:
Ci Vi = Cf Vf
25mg/mL* Vi = 0,05mg/mL*300mL
Vi = 15mg/(25mg/mL)
Vi = 0,6 mL