Its not a breeder or seedbank, clone only strains are only available as clones. Mostly they are special selected phenotypes of a commercial strain, or old classics who was keeped by someone somewhere...

UW Black UW PurpleUW is a marijuana strain that comes with its own superhero origin story. Popular rumor has it that a clone plant was stolen from a certain Pacific Northwest university's medical research lab in the early nineties—in some versions by a rogue graduate student—and has since been a popular top shelf indica. These buds show their university pride with purple coloring, and the dense, sticky buds are at the top of the class when it comes to potency. Almost entirely indica, this strain’s powerful high is sedative and popular for pain relief and insomnia. A mix of tropical fruit and a little spice, the aroma also earns high marks.