Streptavidn-coated products (plates, strips, and I believe beads, can also be purchased from Xenopore Corp. 374 Midland Ave. Saddle Brook, NJ 07662 (201) 796 02000 I'm not affiliated, do not profit from their sales, nor care where you buy your stuff. Dave Knorr dak at apldbio.com Dave (DAK) Knorr