[Histonet] tween detergens

[John Kiernan]

John Kiernan wrote:
> 
> Why use dish-washing liquid, of unknown composition, in
> an expensive procedure in a laboratory? The pure chemicals
> are not expensive and are available from regular suppliers.
> For example, Tween 20 (an old trade-name for
> polyoxyethylene sorbitan monolaurate) costs about US$25
> for 100 ml of syrupy liquid - enough to last a long, long
> time. Even if the price in Europe is 4 times as high,
> this is nothing when compared with the cost of the
> nucleic acid probes and other expendable supplies
> needed for in situ hybridization.
> 
> If your technique calls for a detergent, use the one
> in the published account of the method, at the concentration
> that the author found to be effective. If you do anything
> else you are wasting time and money. Never try to improve
> on a technique before you have tried the original!
> 
> Someone worked hard to optimize the method, and got it
> published in a peer-reviewed journal. It may well be possible
> to make improvements, but the starting point must be
> repeating a procedure that has worked for others. You must
> faithfully follow the original published procedure, using the
> same kind of cells or tissues, and including proper positive
> and negative controls. If you fail to get even a hint of a
> meaningful result, despite doing everything by the book,
> and the appearances of the controls don't help, you may be
> missing out on some simple consideration that is not a major
> part of the method.
> 
> Your mention of "green dish-washing liquid" in the same
> sentence as "autofluorescence" indicates that you (or your
> boss) may not fully understand the ways words are used by
> people who do fluorescence microscopy.
> 
> Autofluorescence  means "self-fluorescence"; it originates
> in the object being examined. Fluorescence derived from a
> staining method is not autofluorescence. Unwanted fluorescence
> from a coloured dishwashing liquid is optical pollution.
> 
> Bottom line. 1. Got to the library. 2. Follow the procedure.
> 
> John Kiernan
> Anatomy Dept, UWO
> London, Canada
> ------------------------------------------------
> Gudrun Lang wrote:
> >
> > Hi all,
> >
> > We are going to run FISH on our ventana benchmark. In the last step we have
> > to wash the slides to remove the liquid cover slip. Until now we use a green
> > dish-washing product for the ihc, but that doesn't fit with the FISH because
> > of autofluorescence.
> >
> > Can anyone give me a hint, if Tween 20 in ?% solution in water is okay?  Or
> > any other well working detergens?
> >
> > Our Ventana-Lady is also looking for a colourless dish-washer, but with no
> > results yet.
> >
> >
> >
> > Thank you in advance
> >
> > Gudrun Lang
> >
> > Linz, Austria
> 
> *** Gudrun Lang: if you identify yourself and your
> laboratory more clearly, you may attract expert
> attention.
> >
> > _______________________________________________
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> > Histonet <@t> lists.utsouthwestern.edu
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-- 
-------------------------------
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
   kiernan[AT]uwo.ca
   http://publish.uwo.ca/~jkiernan/
   http://instruct.uwo.ca/anatomy/530/index.htm
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