use strict;
use warnings;
use Data::Dumper;

my @files = qw(
    12774L1_LacZ.SEE.rc_C06_2008-12-01.ab1
    12774L1_pgK.Neo.2fw_D06_2008-12-01.ab1
    12774L1_SD_B06_2008-12-01.ab1
    12774L1_SU_A06_2008-12-01.ab1
    foo.bar
);
print Dumper(\@files);
@files = grep /^(\d+\D\d)_(LacZ|pgK|SD|SU)(.*)$/,@files;
print Dumper(\@files);

__END__
$VAR1 = [
          '12774L1_LacZ.SEE.rc_C06_2008-12-01.ab1',
          '12774L1_pgK.Neo.2fw_D06_2008-12-01.ab1',
          '12774L1_SD_B06_2008-12-01.ab1',
          '12774L1_SU_A06_2008-12-01.ab1',
          'foo.bar'
        ];
$VAR1 = [
          '12774L1_LacZ.SEE.rc_C06_2008-12-01.ab1',
          '12774L1_pgK.Neo.2fw_D06_2008-12-01.ab1',
          '12774L1_SD_B06_2008-12-01.ab1',
          '12774L1_SU_A06_2008-12-01.ab1'
        ];