I don't take them to the lab, so they can't get stained/contaminated and stay huggable.
Seriously, I wouldn't risk having any of them confiscated but that's just me... ("My... precious!") Now if a science teacher likes them, that's cool!

Also wanted to let you know I used pictures of Mono in a current presentation. It was "customer action shots" from a geek cubicle/household stuff retailer online, and I used it to illustrate Mono transmission via kissing
Still, the place for me to buy my microbes remains science museums or the original websites.