hello
can anyone suggest a good method with detail on how to add antibiotics to media ? and what if i have antibiotics for injection how can i use it in the media ?
Abdullah Mohamed Saad You can prepare a stock of your antibiotic that you want to supplement the media. For example, prepare tetracycline stock 20mg/ml, filter sterilize and store aliquots at -20C (stable for a few months). Let's say you want your final concentration in the agar media to be 20ug/ml, i.e., 1000x dilution. Sterilize agar media (for ex. 400ml) by autoclaving and allow it to cool to 55C in the waterbath. Add 400ul of your tetracyline stock to 400ml of the media (i.e., 20ug/ml), mix well and pour on plates (aseptically).
Hope that helps! I did not understand the second part of your question.
If you have an injectable antibiotic solution, you should be aware that adding to the medium will dilute it. That is why it is not always good to use injectable forms. For example, 1mL in 100mL of culture medium will dilute 100 times !!! It´s better to use powder formulas and build your stock solutions.
Kiran Sreeja Jayan
Victor Monteiro
thank you so much now i understand what to do