Just a small addition, I think there is a missing ")" which I added below..right there at the tail-end ")/g". I also changed this to put the tokens directly into an array without the need for "while".

#!/usr/bin/perl -w
use strict;

my $line = "2006-01-01,Kims,Watson,406,560(centrifuge, refrig.),569,60
+7(dark room),210-211,101(ultracentrifuge),104-105(crystal growth room
+s),660(centrifuge, refrig.)";
 
my @tokens = $line =~ m/([^,(]+(?:\([^)]*\))?)/g;

foreach my $token (@tokens)
{
  print "$token\n";
}

__END__
Prints:

2006-01-01
Kims
Watson
406
560(centrifuge, refrig.)
569
607(dark room)
210-211
101(ultracentrifuge)
104-105(crystal growth rooms)
660(centrifuge, refrig.)
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my @tokens = ($line =~ m/([^,(]+(?:\([^)]*\))?)/g);
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