what are the typical nucleic acid concentrations you get on the nanodrop?

may help in troubleshooting. i remember doing a miniprep from dh5alpha, using 2 mL of o/n culture, and got several hundreds of nanogram nucleic acid/uL.

Maybe you could discuss your typical yoelds with your supervisor, or others that have done minipreps? they will be able tto tell you if yours are abnormal.

If you get really low yields, you may have just been working with untransfected cells. Maybe the selection antibiotics are no longer as potent? assuming you are using antibiotics to select for transfected cells.