As $val = @values assigns the number of elements in the array to $val, your output confirms my suspicion, i.e. that the lines aren't tab separated, so you get only one value in @values (the entire line) from the split.

Try splitting on whitespace: 

#!/usr/bin/perl
use strict;
use warnings;

print " Enter the dilution factor. \n";
chomp (my $df = <STDIN>);
open FILE, "45well.txt" or die $!;
while (<FILE>){
    chomp;
    my @values = split ' ';
    foreach my $val (@values){
        my $DNA_conc = $val * $df * 50 ;
        print "$DNA_conc\n";
    }
}
close (FILE);

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In reply to Re^3: handling tab delimited files by almut
in thread handling tab delimited files by shaludr

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