problems with yields from qiagen spin mini prep kit - (Jan/25/2007 )
our lab has been having major problems with yields from the qiagen spin miniprep kit. the cells we are using are TOP10 from invitrogen. the yields we are getting are as low as 20ng! has any one else had this problem? any ideas?
I have never had problems with GIAGEN kits at all. I think first you should try doing standard minipreps (Sol. I, II y III prepared by your self , pp Isopropanol or EtOH). If it work, the problem is not the kit.
How much culture volume do you use? I use 1.5 or 2.0 ml
Most likely the problem is with the source of your culture. Are you starting from a fresh transformant, plating, and then plucking a single colony and then growing overnight, or are you going from glycerol stock. If going from glycerol stock you must re-streak and then pluck a healthy (large) colony to grow your overnight, of course assuming that your glycerol stock is a log phase culture.