High molecular weight PCR artefact

A student in our lab is reproducibly seeing a high M.Wt band (it only
enters the gel a mm or so after an hours electrophoresis in 1% agarose)
after PCR of genomic DNA. We think we've ruled out bacterial
contamination (-ive Taq control does not show the band - this also rules
out the possibility that it's genomic DNA), or any reagent artefact, as
fresh reagents also show the problem, and we can amplify a house-keeping
gene (28S rDNA) without ... ...

Last update 18-Nov-2000, Rating Good of 0 votes.