sub load_parents
{
    my ($parent_index) = @_;
    my %parents;

    open (FH, "< $parent_index") or die "could not open file $parent_index for reading:$!";

    while (my $line = <FH>) {
      chomp($line);
      my ($index, $parent) = split(/\t/, $line);
      $parents{$index} = $parent;
    }
    return \%parents;

}

sub load_primers
{
    my ($primer_index) = @_;
    my %primers;

    open (FH, "< $primer_index") or die "could not open file $primer_index for reading:$!";

    while (my $line = <FH>) {
      chomp($line);
      my ($index, $primer) = split(/\t/, $line);
      $primers{$index} = $primer;
    }
    return \%primers;

}