"The colour of the pen! That I hold in my hand is Rr.rr.ROYAL BLUE!"
(Liar, liar;1997)

Today's tutorial was inspired by a student from my uni, who has got a quite unusual pen - something like
this. Upon closer inspection, it turned out it isn't what I expected - it just pretends to be a syringe, but in fact there is a normal ballpen inside it. But, it has inspired me to further experiments, which were succesful and ended with my new blog entry. I especially recommend this tutorial for medical students :)