in reply to Useless use of private variable in void context at

Ignore me, I missed the "rand" statement....

Grampa already gave you a good answer, so I won't belabor that. I wanted to mention, though, that you can build your string even more simply using the "x" operator:

my $aa = 'A' . 'T' . 'C' . 'G'x5003;

...roboticus

When your only tool is a hammer, all problems look like your thumb.