chemidoc mp multimode imager  (Bio-Rad)

Journal: Proceedings of the National Academy of Sciences of the United States of America

Article Title: A fluorescence-based genetic screen reveals diverse mechanisms silencing small RNA signaling in E. coli .

doi: 10.1073/pnas.2106964118

Figure Lengend Snippet: Fig. 1. A chromosomal tandem fluorescence reporter system allows facile monitoring of endogenous sRNA activity in E. coli. Schematic of the chiP (A) or sodB (D) dual-fluorescence reporter. Colony fluorescence on LB agar for reporter strains carrying translational fusions to chiP (B, WT [JC1200]; ΔchiX [JC1244]) or sodB (E, WT [JC1246]; Δfur [JC1248]; ΔfurΔryhB [JC1252]; and ΔfurΔhfq [JC1269]) was imaged using the Bio-Rad ChemiDoc MP Imaging System. Bright field imaging (B.F.) was used to visualize all colonies on the plate. chiP (C) or sodB (F) reporter fluorescence from cultures grown in LB for 6 h was measured using the TECAN Spark 10M microplate reader. Representative images for colony fluorescence are shown. For fluorescence quantification, three to six individual clones of each strain were grown and measured in 96-well microplates; data are plotted as mean and SD. A detailed description of fluorescence measurement and quantification is included in Materials and Methods.

Article Snippet: To visualize colony fluorescence, E. coli cells were streaked on LB agar supplemented with appropriate antibiotics and grown at 37 °C for 16 h. The next day, colonies on agar were directly imaged using the Bio-Rad ChemiDoc MP Imaging system at multimode (Cy2 for GFP, Cy3 for mCherry and Ponceau S for bright field, auto optimal exposure).

Techniques: Fluorescence, Activity Assay, Imaging, Clone Assay