One of my students recently asked me if you can obtain a DNA sample from that goop you get in the corner of your eye. I was inclined to say no but I thought I'd check with someone more authoritative than me on the subject.

Thanks for your help.

One can extract DNA from any living cell that has a nucleus. The material you describe would almost certainly have cellular material so the answer in theory would be yes, but difficult technically with so few cells (though forensic molecular biology is now advancing rapidly and single cell finger printing is used by some).

Here is a cautionary note about 'touch DNA' being used in forensic medicine - http://www.nature.com/news/forensic-dna … le-1.18654