State Key Laboratory for Molecular Virology and Genetic Engineering, Chinese Center for Disease Control and Prevention
Manufacture protocol
The cDNA microarrays have 3943 PCR-amplified sf301 (S. flexneri 301 strain) open reading frames (ORFs) and other 409 spots represented as controls. Excluding replicated spots for 57 ORF, the microarrays allowed us to analyze the expression of 3771(93.3%) chromosome coded ORFs and 113 (72.9 %) plasmid-borne ORFs. Sf301 ORFs were amplified with ORF-specific primer pairs (Invitrogen). Amplified products which mostly ranged between 300 and 700 bases in length were purified by using MultiScreen-PCR plates (Millipore). Concentrations of the PCR products were measured by Spectra MAX 190 (Molecular Devices).Then the PCR products were readjusted to 100 ng/ul of concentration with deionized water and double diluted into spotting solution containing 60% DMSO. The PCR products were spotted onto gamma amino propylsilan coated GAPII slides (Corning) by using OmniGrid ™ microarrayer (GeneMachines).