Knight: Addition of 3' A-overhangs

Overview
This protocol adds 3' A-overhangs to a PCR product rendering it suitable for TA cloning.

Materials

 * Taq polymerase
 * A heat block equilibrated to 72&deg;C

Procedure

 * 1) After amplification with the proofreading polymerase, place vials on ice and add 0.7-1 unit of Taq polymerase per tube. Mix well. It is not necessary to change the buffer. A sufficient number of PCR products will retain the 3´ A-overhangs.
 * 2) Incubate at 72&deg;C for 8-10 minutes (do not cycle).
 * 3) Place on ice and use immediately in the TOPO cloning reaction.