Evaluation of the redox dye 5-cyano-2,3-tolyl-tetrazolium chloride for activity studies by simultaneous use of microautoradiography and fluorescence in situ hybridization.
Three microscopic in situ techniques were used simultaneously to investigate viability and activity on a single-cell level in activated sludge. The redox dye 5-cyano-2,3-tolyl-tetrazolium chloride (CTC) was compared with microautoradiography (MAR) and fluorescence in situ hybridization (FISH) to indicate activity of cells in Thiothrix filaments and in single floc-forming bacteria. The signals from MAR and FISH correlated well, whereas only 65% of the active Thiothrix cells and 41% of all single cells were detectable by CTC reduction, which mainly targeted the most active cells.
Nielsen
Jeppe Lund
JL
Department of Environmental Engineering, Aalborg University, DK-9000 Aalborg, Denmark.
Aquino de Muro
Marilena
M
Nielsen
Per Halkjaer
PH
D001345:Autoradiography; D005456:Fluorescent Dyes / Q000378:metabolism*; D020563:Gammaproteobacteria / Q000166:cytology / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D010084:Oxidation-Reduction; D012722:Sewage / Q000382:microbiology; D013778:Tetrazolium Salts / Q000378:metabolism*
D005456:Fluorescent Dyes; D012722:Sewage; D013778:Tetrazolium Salts