I need to attach a single strand DNA oligo to an antibody molecule. Any good suggestions on the strategy? I know there are some kits available. But I want to hear from those who have experiences which method is the best in terms of efficiency and easiness of use. After conjugation, the DNA oligos need to be removed. Any suggestions on that too? The DNA oligo is about 18kD (60 nucleiotide). Size exclusion chromatography would be an option. But I cannot find a column that can deal with a small volume (100 ul).