Today we’ll meet at 1.30 pm in aula F pr to finish together our “pick-primers.pl” program. During last lab most of you got Primer3 running with our custom parameters. Primer3 output consists in a list of possible primer pairs.
We want to blast each primer against reference contigs to check how many sequence similar to it are present in the genome. This is a pivotal test to have specific PCRs. To make this we design a subroutine called ‘blast’ that takes as input a sequence (primer) and blast it against the contigs and parses the output returning a list of hints. In particular we consider dangerous those aligment long as the query -2 bp. Thus if our primers is long 20 and the match is 15 we will discard it. If the match with another contig is 18 bases long, we will report this to the user.