brain0001
lung0001
brain00002
kidney0003
brain00003

##</code><code>##

$data = "mydata.list";

@pref = ("brain", "lung", "kidney");

%dfs = map {$_ => ()} @pref;

open DF, "<$data";
while(my $line=<DF>){
	chomp($line);
	foreach $pat (@pref){
		push @{$dfs{$pat}},$line if ($line=~/$pat/);
	}
}
close DF;