title: Application of glutaraldehyde for the staining of esterase-active cells with carboxyfluorescein diacetate.
abstract: Staining of esterase-active bacteria with carboxyfluorescein diacetate (CFDA) has been used to evaluate the viability of various types of cell. However, the outer membrane of Gram-negative bacteria prevents CFDA from permeating into the cell. Although EDTA can increase the permeability of the outer membrane allowing CFDA to enter the cells, it was experimentally confirmed that there is still considerable difficulty in visualizing viable cells due to passive diffusion of carboxyfluorescein (CF), a hydrolyzed product of CFDA, out of the cells. We found that glutaraldehyde enhances the discriminative recognition of esterase-active Gram-negative bacteria under microscopic observation by improving the efficacy of staining. We believe the successful staining in the presence of glutaraldehyde is due to two separate effects: an increase in the permeability of CFDA into the cell and prevention of leakage of CF out of the cell.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Morono
authors.forename: Suguru
authors.initials: S
authors.lastname: Takano
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Miyanaga
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Tanji
authors.forename: Hajime
authors.initials: H
authors.lastname: Unno
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Hori
mesh_terms: D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival; D015169:Colony Count, Microbial / Q000379:methods*; D004950:Esterases / Q000378:metabolism*; D005452:Fluoresceins / Q000493:pharmacokinetics*; D005976:Glutaral / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D007089:Image Enhancement / Q000379:methods; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D005452:Fluoresceins; C027780:carboxyfluoresceindiacetate; D004950:Esterases; D005976:Glutaral