Make sure your ligation worked, and you have the right selection for the plasmid.

How to check ligation is worked or not.

Choice of plasmid is correct.

double check also your plate and prepare fresh plate every time for the cloning transformation.

After the transformation, which media do you use for the incubation??

Riccardo

@riccardo..there is no colony in plate.i.e no transformation..

Media used is LB

I was talking about the media that you used after the thermal shock/ elettroporation. So in theory you transform your cell then you incubate at 37C for 1 h then you plate. During the cloning when i used the LB for the incubation i didn't have colonies. Try to use the SOC media or other more nutrient media. you can also increase the 37C incubation time before plate your cloning

Run a gel of your ligated sample alongside a sample taken before ligation. You should see the difference. Note SOC media may give you a 2-fold increase in the number of colonies, but use of LB media should not kill your transformation.

@Hua Xao...what do you mean by before ligated sample.plz explain

Did you perform a digestion before the ligation ? If so, did you checked this digestion worked properly ?

Yes but how to conform that ur digestion is complete