Sodium 75Selenite supplier for metabolic labeling

My lab works with a potential selenoprotein, and we would like to confirm this by metabolic labeling in tissue culture using 75Se and subsequent autoradiography of the protein lysate.

Does anyone know where to find a vendor who carries selenium 75 in a bioavailable form such as sodium selenite? I've been searching and haven't had any luck thus far and our Perkin Elmer rep was stumped. Thanks! Any info would be greatly appreciated.

Bioconcentration mechanism of selenium by a coccolithophorid, Emiliania huxleyi.
Plant Cell Physiol. 2004 Oct;45(10):1434-41.

http://pcp.oxfordjournals.org/cgi/content/full/45/10/1434#SEC4

These guys obtained [75Se]selenite (H2SeO3 in 0.1 M HCl, 111 MBq ml1, 4,847 GBq g1 from Isotope Products Laboratories, Burbank, CA, U.S.A.

I know that although Amersham used to sell sodium 75Se selenite they have now discontinuted it and don't have a replacement product.