Questions About the Termini of PCR Products

[Brian Hjelle]

I have 2 questions about PCR cloning.

1. Is it recommended or common now to try to repair the ends of PCR
products (blunt-ended) before trying to clone them into a vector? I
understand the ends are often ragged.

2. In designing a new primer that contains a 5' restriction site, I
know you should place a few extra bases 5' of the recognition site.
Are some bases better to use in this function than others?

Thanks in advance!

Brian