In situ hybridization of microcolonies using catalyzed reporter deposition with tetramethylbenzidine: a method for detecting low numbers of bacterial cells in drinking water
In this study, catalyzed reporter deposition in situ hybridization (CARD--ISH) with tetramethylbenzidine (TMB) was used for rapid detection of the food pathogens Salmonella typhimurium and Escherichia coli. The bacteria in a sample were concentrated by membrane filtration. The filter membranes with...
Saved in:
Published in | European food research & technology Vol. 227; no. 4; pp. 995 - 999 |
---|---|
Main Authors | , , , , , , , |
Format | Journal Article |
Language | English German |
Published |
Berlin/Heidelberg
Berlin/Heidelberg : Springer-Verlag
01.08.2008
Springer-Verlag Springer Springer Nature B.V |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | In this study, catalyzed reporter deposition in situ hybridization (CARD--ISH) with tetramethylbenzidine (TMB) was used for rapid detection of the food pathogens Salmonella typhimurium and Escherichia coli. The bacteria in a sample were concentrated by membrane filtration. The filter membranes with the cells thus removed were incubated on nutrient agar for 4-5 h to allow the formation of microcolonies. Instead of fluorescent tyramide, 3,3',5,5'-tetramethylbenzidine (TMB), which yields a blue precipitate, was used for signal amplification after in situ hybridization. Microcolonies amplified with TMB produced blue signals, which were sufficiently intense to allow visual evaluation either using a stereomicroscope, or even with the naked eye. Therefore even low cell numbers of hygienically critical bacteria can be detected on the filter membrane without a protracted examination. This enables the detection of low cell numbers (<10 cfu) in a sample of 100 ml tap water within 9-10 h. |
---|---|
Bibliography: | http://dx.doi.org/10.1007/s00217-007-0811-9 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1438-2377 1438-2385 |
DOI: | 10.1007/s00217-007-0811-9 |