Protocol Online logo
Top : Forum Archives: : Molecular Biology

probe preparation: Dig labeling - (May/18/2006 )

Hi everyone,

I would like label a probe with length around 25bp. Is this impossible to label it using Dig labeling system? Or can I make some modifications to make it possible?

Thank you very much for all your attention!



Easiest would be to order an oligo of this size which was already DIG labeled. Many oligo companies will do this for you. Else, you could order a pair of 18-20 bp oligos which overlapped and extend them with a PCR reaction having DIG-dUTP, which is a great way of making DIG labeled probes. You can do an asymmetric PCR to favor creation of the directional probe you want, and to make it single stranded. Of course, you need to make sure that you'll be adding some T's during the extension process.