Escherichia coli biofilm: mono-species culture vs. mixed-species culture. Escherichia coli K-12

Transcription profile of Escherichia coli cells in mono-species pure biofilms was compared to that of E. coli cells in E. coli-Stenotrophomonas maltophilia dual-species biofilms. E. coli cells were separated from dual-species biofilms before total RNA extraction to eliminate possible cross hybridization from S. maltophilia transcripts. The separation method was developed by combining the use of reagent RNAlater and immuno-magnetic separation. Pure E. coli biofilms were processed with the same separation protocol before RNA extraction. Overall design: Two condition experiments: E. coli mono-species biofilm vs E. coli in mixed-species biofilm. Two biological replicates with independently grown and harvested biofilms. Each biological replicate has two or three technical replicates of hybridization on microarray slides. Each slide has three built-in replicates for each probe.