FAQ: Is it necessary to purify PCR products when doing DNA assemblies using either NEBuilder HiFi DNA Assembly Master Mix or Gibson Assembly Master Mix?

Purification of PCR products is generally not necessary. You can use unpurified PCR products directly, as long as the total volume of unpurified PCR products in the Assembly reaction is 20% or less. If greater amounts of PCR products are used, we recommend the use of a column-based cleanup kit (Monarch PCR & DNA Cleanup Kit, NEB #T1030).  In the event that multiple fragments are amplified or the presence of primer dimers is observed, we recommend optimizing the PCR step for best results.