RE: Analysis of sirius red with polarized light

From:Gayle Callis

Terry makes a good point particularly on positive control sections.   Some
histobooks suggest cutting sections for amyloid detection at more than 5 um
i.e. 10 um.  Could it be due to smaller deposits showing up better with
thicker sections?

At 03:54 PM 12/17/02 +0000, you wrote:
>It is a simple fact that small amounts of amyloid will not polarise to the
extent (vividness) of large amounts. The struggle then is to identify them.
If they stain with Sirius red are in an appropriate place, and have the
right appearance, then any amount of light to polarise it is OK with me. 
>In parenthesis, why are the controls for amyloid always from solid amyloid
spleens etc.? That is to say - loaded.
>Surely the faintest amount of amyloid is the appropriate control.
>Terry L Marshall B.A.(Law), M.B.Ch.B., F.R.C.Path
>Consultant Histopathologist
>Rotherham General Hospital, Yorkshire
>-----Original Message-----
>From: []
>Sent: 17 December 2002 15:16
>Subject: Analysis of sirius red with polarized light
>Dear all, 
>In the process of analysis of our picro sirius red stained sections we ran 
>into a discussion on the microscope prefs. We could not come to a conclusion 
>as to how much light must be given. We use 2 polarization filters in crossed 
>position. Some people want to give minimal light in order to prevent 
>overestimation of collagen content, total background is black. Others say to 
>give full light, but than the background becomes somewhat blueish, which 
>cannot be turned to black by adjusting the filters. 
>Does anyone have experience with different lighting on sirius sections? Or
>anyone aware of literature in which this problem is discussed. 
>Thanks in advance, 
>Dolf Segers 
>Dept. of Experimental Cardiology 
>Thoraxcentre, Erasmus MC Rotterdam 
>The Netherlands 
Gayle Callis
Research Histopathology Supervisor
Veterinary Molecular Biology - Marsh Lab
Montana State University - Bozeman
S. 19th and Lincoln St
Bozeman MT 59717-3610

406 994-6367 (lab with voice mail)
406 994-4303 (FAX)


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