Fluorescent beads are used as calibration standards in fluorescence microscopy, so I refer you to the confocal microscopy listserve thread on this topic: http://listserv.acsu.buffalo.edu/cgi- bin/wa?A2=ind0202&L=confocal&P=R13779 Choose "Next in topic", the fourth button on the graphical toolbar, to see the responses. Three possible sources: Spherotech, Beckton Dickinson, and Pharmingen Regards, Chris On Wednesday, June 26, 2002, at 05:56 pm, andreacarbonaro wrote: > Dear mems-friends, > > does anybody know where I can buy fluorescent nano-beads for filtration > tests? > > thank you very much > > Andrea Carbonaro -- Christopher F. Blanford Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK Phone: (44)/(0)-1865-282603; Fax: (44)/(0)-1865-272690 PGP keyID: 8D830BC9 http://pgp.mit.edu/