use strict;
use warnings;

while (<DATA>) {
    if (/^(\d+\D\d)_(LacZ|pgK|SD|SU)(.*)$/) {
        print "match: $_";
        print '    $1', " is $1\n";
        print '    $2', " is $2\n";
        print '    $3', " is $3\n";        
    }
    else {
        print "no match: $_";
    }
}

__DATA__
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