An innovative brilliant blue FCF method for fluorescent staining of fungi and bacteria

Abstract

Most natural and synthetic dyes currently used for microbial fluorescent staining are toxic or carcinogenic and are harmful to animals, humans and the environment. A food dye for microbial staining, brilliant blue FCF, was used as an alternative to lactofuchsin and lactophenol blue. Brilliant blue FCF shows pronounced microbial cell fluorescence staining of an array of pathogenic/toxigenic (Fusarium granunearum 3- and 15-acetyldeoxynivalenol chemotypes, and Escherichia coli O157:H7) and beneficial fungi and bacteria (Trichoderma harzianum and Bacillus subtilis). Brilliant blue FCF has no toxic effects on the microbes tested and is inexpensive.

Key words::

• brilliant blue FCF
• Escherichia coli 0157:H7
• fluorescence microscopy
• food dye
• Fusarium graminearum
• microbial dye

Acknowledgments

This research was supported financially by Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant and Saskatchewan Agriculture Development Fund (ADF) to VV, Dean Scholarship to HWC and Departmental Devolved Scholarship to YKG. We thank Michelle Hubbard for assistance in confocal laser scanning microscopy.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.