problem about blue white screening
Posted 22 February 2011 - 06:12 AM
i did the blue white screening for my ligasion, only several colonies(less than 15 colonies), white, grow on the plate. i picked the white colonies and grew them in fresh plates(LB+Amp). Then did the colony PCR to check if my target fragment was inserted. According to the colonies, white, resistant to Amp, i thought my DNA fragment shoule be inserted in, but, no, nothing:(((
i will be very appreciate if someone could explain what's the white colonies, and why they can grow on the LB+Amp and behave white color without my DNA fragment inside (the ligasion is double enzyme digested pcr fragment and also double enzyme disgested plasmid, NOT pGEM-T...).
thanks a lot!
Posted 22 February 2011 - 07:25 AM
Posted 04 March 2011 - 05:25 AM
whatever, i did another round. Thanks a lot!!