Silly glass plate question

[Lassner]

This is probably a stupid question, but ...

Has anybody tried using ordinary glass plates on their ABI373 sequencers. 
Since the laser and flourescent wavelengths are visible light, I was
wondering if I could go to the local glazier and have ordinary glass plates
cut to the proper size.  Or is there some special optical quality glass that
would be suitable but still not cost the arm and a leg that ABI charges.