purify radioactive labeled oligonucleotides - problems with the yield (Feb/16/2007 )

I'm having a problem with purifying my oligonucleotides.I labeled them with 33P-dATPs. There are still dATP's and unlabeled oligonucleotides in my solution but I want only the labeled oligonucleotides.A column and/or ethanol precipitation don't really work because I'm using only 0.2 pmol oligo. Does somebody here has some tips on increasing my yield? thanks in advance

woo~~~~~~~~ 33P, must cost you futune.

well, as much as i know, it is not quite possible to get pured oligos without unlabeled dATP after column purification.
One thing you may try is to get it run in the gel and get it gel purified. But it is time-consuming and needs lots of labour work.