[Histonet] Postive charge slides, section loss and drying

[Gayle Callis]

>
>Jeff,
>
>It was pointed out to us (by Marcia  (sp?) from Newcomer Supply) - it is 
>important  HOW a section is picked up.  One should make sure the tissue 
>portion of paraffin section comes into contact with positive charged 
>surface very quickly during picking up motion.  This permits the tissue to 
>adhere better, without so much water underneath it,  onto the positive 
>charged surface. IF the section is in good contact with the slide, there 
>will be better interaction of plus charge to tissue,  and you would not 
>have to depend so much on paraffin melting to allow water to escape under 
>this + / - seal.
>Vertical draining os sllides in a polypropylene slide holder is important 
>before loading slides in horizonal position in a rack.  We keep a razor 
>blade handy to release water blebs at section edge before racking up and 
>drying.  We have actually dried sections on Plus charge slides for 1 hour 
>at 60C and still had water present under paraffin.  This ceased after 
>tweaking picking up technic and vertical drying.
>
>At 09:53 PM 12/9/2004, you wrote:
>
>>1)  Drying (most common).  When you room temperature dry the slides, the 
>>water will dry from the outside in.  Once the water is out from the edge 
>>of the slide, the paraffin sort of adheres itself to the slide around the 
>>tissue, creating a seal that doesn't allow any more water to escape from 
>>under the paraffin.  It can sit there for a month and still have water 
>>trapped under the tissue in this condition.  When you put the slides in 
>>the oven, the paraffin melts allowing water to escape from under the seal 
>>and under the tissue, thereby allowing the tissue to fully adhere to the 
>>slide without any water barrier separating any part of it.

Gayle Callis
MT,HT,HTL(ASCP)
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-6367 (lab with voice mail)
406 994-4303 (FAX)