Materials: Difference between revisions
Barry Canton (talk | contribs) |
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====Notes==== | ====Notes==== | ||
There don't appear to be any dyes that selectively stain live cells. When people want to detect live cells, I think that what they do is the following: "The principle of this approach is to use simultaneously a permeant (SYBR Green [more recently SYTO green]; Molecular Probes) and an impermeant (propidium iodide) probe and to take advantage of the energy transfer which occurs between them when both probes are staining nucleic acids. A full quenching of the permeant probe fluorescence by the impermeant probe will point to cells with a compromised membrane, a partial quenching will indicate cells with a slightly damaged membrane, and a lack of quenching will characterize intact membrane cells identified as viable." From Applied and Environmental Microbiology, October 2001, p. 4662-4670, Vol. 67, No. 10. So most stains that people bill as live cell stains are only membrane permeant stains and therefore stain both live and dead cells. | There don't appear to be any dyes that selectively stain live cells. When people want to detect live cells, I think that what they do is the following: "The principle of this approach is to use simultaneously a permeant (SYBR Green [more recently SYTO green]; Molecular Probes) and an impermeant (propidium iodide) probe and to take advantage of the energy transfer which occurs between them when both probes are staining nucleic acids. A full quenching of the permeant probe fluorescence by the impermeant probe will point to cells with a compromised membrane, a partial quenching will indicate cells with a slightly damaged membrane, and a lack of quenching will characterize intact membrane cells identified as viable." From Applied and Environmental Microbiology, October 2001, p. 4662-4670, Vol. 67, No. 10. So most stains that people bill as live cell stains are only membrane permeant stains and therefore stain both live and dead cells. | ||
== Agarose gels == | |||
#[[1X TAE]] | |||
#[[Loading dye]] | |||
#[[DNA ladder]] | |||
#[[EtBr | Ethidium bromide]] |
Revision as of 14:55, 17 May 2005
Media
Defined Media
Standard Media
Antibiotics
Enzymes
Phosphatases
RNA Polymerases
DNA Polymerases
Reporters
Dyes and stains
Useful links
http://www.probes.com/handbook/sections/0801.html
http://www.probes.com/handbook/sections/1502.html
Individual dyes
- Acridine Orange
- Carboxyfluorescein Diacetate
- DAPI
- Fluorescein diacetate
- Hoechst 33342
- Propidium iodide
- SYBR Green I
- SYBR Green II
- SYTO
Notes
There don't appear to be any dyes that selectively stain live cells. When people want to detect live cells, I think that what they do is the following: "The principle of this approach is to use simultaneously a permeant (SYBR Green [more recently SYTO green]; Molecular Probes) and an impermeant (propidium iodide) probe and to take advantage of the energy transfer which occurs between them when both probes are staining nucleic acids. A full quenching of the permeant probe fluorescence by the impermeant probe will point to cells with a compromised membrane, a partial quenching will indicate cells with a slightly damaged membrane, and a lack of quenching will characterize intact membrane cells identified as viable." From Applied and Environmental Microbiology, October 2001, p. 4662-4670, Vol. 67, No. 10. So most stains that people bill as live cell stains are only membrane permeant stains and therefore stain both live and dead cells.