1 EXHIBIT 99.A PURCHASE AGREEMENT THIS PURCHASE AGREEMENT (the "Agreement") dated as of February __, 1999 by and between ________________ ("Buyer") and Sean B. Carroll, an individual residing in the State of Wisconsin ("Seller"). R E C I T A L S: A....Purchase Agreement • March 10th, 1999 • Ophidian Pharmaceuticals Inc • Services-commercial physical & biological research • Illinois
