Hi Rupali,

During the chemical synthesis of the olingonucleotide primers you can ask the company/vendor to attach the biotin molecule at the 5' end...

Thanx sir, what else are the solutions if biotinaylated primers are not available and one has to attach biotin to it manually in lab..

Why just the 5' end/ I use a kit that labels on dCTP. Assuming that you are using this for blotting, I would think this would give you a stronger signal. Kit is North2South Complete Biotin Random Prime Labeling and Detection Kit from Pierce.

Hi Rupali

As suggested above if possible ..try to find out if you can use some other approach ..for labelling and detection...like labeling 3'-end or PCR product labeling...or use 5'end radioactive labelling......but if your experiment only needs 5'-end labeling with biotin....it may be little bit tricky.....see if some of the artciles attached below can be of use to you...most of these use chemical steps for additing the biotin moeity to the 5'end.....or you can also use RNA ligae mediated approach...however I still feel...if you plan to use this primer several times in your analysis...get it synthesized fresh with biotin group attached to 5' end...it will work out cheap compared to other protocols..

bye

Second article

Third article