Just another way - using the transliteration operator. 
my $dna = 'TAgc';
my $rc = uc reverse $dna =~ tr/ATGCatgc/TUCGtucg/r;

print "$dna\n$rc";

[download]
Prints 
TAgc
GCTU

[download]

In reply to Re: Trying to use substring to find a reverse complement in DNA, by Anonymous Monk
in thread Trying to use substring to find a reverse complement in DNA, by tryingnottofailmytes

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