Does anyone know if the purification of PCR fragments (from agarose gel or with a column to eliminate other bands and/or oligonucleotides) before cloning in T/A vectors is a critical step ?? Thanks for yours answers. Regards, Christophe. -- Christophe JACOB Lab. Forest Biology University Nancy 1 BP 239 54506 VANDOEUVRE email: jacob at scbiol.u-nancy.fr