$seq="ACGGGAGGACGGGAAAATTACTACGGCATTAGC";
print "Initial seq is:\n".$seq."\n";

my $complement=$seq;
$complement =~ tr/ACGTacgt/TGCAtgca/;
print "Complement is:\n".$complement."\n";

$reverse = reverse($complement);
print "Reverse complement is:\n".$reverse."\n";