This protocol was designed to generate directionally end-labeled probes for DNaseI footprinting but it can be used for any application that requires end-labeled DNA probes.
Thaw100 mM stocks (NEB or Boehringer Mannheim) on ice and dilute 10-fold in Q.
dNTP Mix
21
3
Note: leave out the dNTP which will be used for labeling of the chosen restriction site (i.e.
ProcedureDigest 2
•
• Resuspend the pellet in 19
25
5
5
1
Incubate at room temperature for 30'.
• Phenol/chloroform extract and EtOH ppt. Resuspend in 16
• Gel purify by running out the restriction digest (5 minutes 100 mA) on a 1% minigel and spin purifying (Protocol D.5).
• Resuspend the purified fragment in 100
• Count 1
• Probes labeled using this protocol are usually good for 1-2 weeks but the best results are obtained when the probe is used within the first few days after labeling.