[Histonet] Re: Testing for shrinkage

[Bryan Hewlett]

Hi Bryan,

Good to hear from you! How are you keeping?

You are quite correct regarding Baker's data.
He engages in some discussion on this matter, mentioning the microscopic 
shrinkage and gives data on both whole cell volumes as well as nuclear 
volumes.
I don't find his figures high but actually very accurate, in fact in my 
experience many clinical labs have much higher shrinkage factors than 
Baker's
due to non-optimized processing.

But then that doesn't surprise old codgers like us does it?

Cheers,

Bryan

----- Original Message ----- 
From: "Bryan Llewellyn" <llewllew <@t> shaw.ca>
To: "Histonet" <histonet <@t> lists.utsouthwestern.edu>
Sent: Wednesday, August 25, 2010 12:45 PM
Subject: [Histonet] Re: Testing for shrinkage


> Taking simple measurements of pieces of tissue and then repeating the 
> measurements following fixation, processing and infiltration will 
> certainly allow for estimating the degree of macroscopic shrinkage. 
> Unfortunately, this is not the only shrinkage that takes place, as a 
> simple look at the finished section with a microscope will show.  Cells 
> separated from other cells, fibres split off from other fibres, and the 
> like, are all due to microscopic shrinkage and are in addition to the 
> macroscopic shrinkage determined by simple measurement of tissue.
>
> I have always presumed that this is why Baker's figures appear to be quite 
> high, because he factored in all forms of shrinkage, not just the obvious.
>
> Bryan Llewellyn
>
>
> ----- Original Message ----- 
> From: "gayle callis" <gayle.callis <@t> bresnan.net>
> To: "'Edwards, Richard E.'" <ree3 <@t> leicester.ac.uk>; 
> <histonet <@t> lists.utsouthwestern.edu>
> Sent: Wednesday, August 25, 2010 8:59 AM
> Subject: Testing for shrinkage RE: [Histonet] shrinkage/a howlong is a 
> piece of string type question
>
>
>> Have you ever thought of doing a shrinkage test?  Take a tissue specimen,
>> and xerox or use a flat bed scanner.  Put fixed sample between plastic
>> sheets, and scan it as unfixed tissue, fixed before processing and then
>> after processing while in a faced paraffin block. Take all the 
>> measurements
>> and then do the calculations./    We used to xerox large stained bone
>> sections, a clever way of getting a precise macro-images of a huge 
>> specimen
>> to show gross features of a defect. This did a better job than trying to 
>> do
>> a macro-photo with a camera or through a microscope (the latter doesn't
>> happen).
>>
>> Years ago, when preparing for HTL exam practical, the samples e.g. tissue
>> sections submitted had to be within a certain size range, and it was duly
>> noted that after processing, the samples had shrinkage.  This required 
>> going
>> back to fixed tissue and cutting a bigger piece to compensate for the
>> shrinkage and have a final correct sample/section size to follow the
>> practical rules.
>>
>> As for GMA, there is a special processing schedule given to me that does 
>> not
>> use alcohol dehydration (for lipid staining work).  This protocol uses an
>> GMA/watergradient since GMA is miscible with water.  I would think there
>> would be even less shrinkage with a water/GMA gradient and the source of
>> shrinkage would come from the heat of polymerization and possibly a bit 
>> from
>> kind of fixative used.  The heat can controlled to some degree by doing
>> polymerization on ice, or in a refrigerator, with the round JB4 metal 
>> chucks
>> to dissipate the heat.
>>
>> Once again, I agree with Bryan Hewlett's assessment of shrinkage.
>>
>> Gayle Callis
>> HTL/HT/MT(ASCP)
>> Bozeman MT
>>
>>
>> -----Original Message-----
>> From: histonet-bounces <@t> lists.utsouthwestern.edu
>> [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Edwards,
>> Richard E.
>> Sent: Wednesday, August 25, 2010 7:50 AM
>> To: histonet <@t> lists.utsouthwestern.edu
>> Subject: [Histonet] shrinkage/a howlong is a piece of string type 
>> question
>>
>>
>>
>> Many  thanks  to  all who  responded, for  paraffin processed tissues the
>> figures  suggested for the amount of shrinkage found or expected were :-
>> "more than 
>> 5%":"5-10%":"10%"(twice):"10-15%":"20%":"25%":"30-35%":"30-40%",
>> one  responder felt it was "noticeable" and another thought it was a 
>> "fairy
>> tale" concocted by pathologists............unsurprisingly many 
>> responders
>> thought that  the  degree  of  shrinkage was dependent on the fixative 
>> used,
>> processing schedule and the nature of the tissue itself, e.g. amount of
>> lipid present. As far  as  shrinkage with GMA processed tissue go, a 
>> single
>> response of "5%"  was quoted.
>>
>>                                                       Richard  Edwards
>>
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