Protocol Online logo
Top : Forum Archives: : Molecular Biology

How little competent cell do you use for transformation - (Sep/14/2004 )

Usually companies selling competent cells encourage you to use as much as possible and 100 ul is suggested. Because they are not cheap, I have used 50 ul per transformation. How much can I further scale down?



I routinely use 25 ul. Note that i am cloning single PCR bands for sequencing, not building a library! I sometimes have low efficiency problems, but I don't think this is related to using only 25 ul. I routinely get several hundred colonies (I plate the entire transformation reaction).


thank you. That sounds like a reasonable number and I will try it.