Amersham Biosciences received US Patent No. 6,569,674, “Method and apparatus for performing biological reactions on a substrate surface.” The patent covers a system for removing gas bubbles from a reaction chamber comprising a flexible layer affixed to a substrate layer holding oligonucleotide binding sites, in which biological reactions are performed. The system describes methods and apparatus for removing gas bubbles from the reaction chamber where target molecules contained in a sample fluid react with probe.