use strict;
use warnings;

my $string = "";
my $DNA;
{ 
		local $/=undef; 
		$DNA = <DATA>;
} 
chomp($DNA);
$DNA =~ s/\n/,/g;
$DNA = "{$DNA}";
$string .= $DNA;
print $string;

__DATA__
C1G1
C1G2
C2G1