[Histonet] Detailed Re: Attaching GMA sections to slides

Gayle Callis gayle.callis <@t> bresnan.net
Wed Dec 3 10:37:59 CST 2008


You did not say what you were doing to the sections after mounting them on slides as this may be a factor for section lifting off other than  

 It is important to have perfectly flat sections, so make sure the blades or glass knife is very sharp. GMA is designed for use for thin sections 3 um or thinner, and when we had 4 to 5 um thick sections, lift off was more of a problem.  You did not say how thin your sections were?   If thick sections are not in flat contact with slide at pickup, this may be a factor.  

We never had to weigh down GMA sections.    We preferred glass knives and used a new knife to section each block.  The knife used for a block became the trim knife for the next block.    We floated each individual GMA sections onto room temperature distilled water filled to the top of a glass staining dish.  It takes a bit of practice to lay the flightly little plastic sections on the water, but it can be done.  Don't use warm water baths as this helps to release fumes from the plastic that are sensitizing, avoid becoming allergic to this plastic. 

Sections were picked up onto a very clean glass slide, with slide held almost vertically.  We have used plain uncoated glass slides, washed in hot detergent, rinsed well with tap water then distilled,  dipped in acetone or absolute ethanol to dry. The surface of the slide was pristine, without any dirt, dust or oily residue. A labor intensive job to wash slides.  We later found Plus charge slides (Erie)  worked well.   We simply air dried sections, then went to a 56C incubator for 60 minutes.   

There are tricks to prevent GMA sections from coming off the slide.  Our sections did not release from slides unless we overexposed them to  95% alcohol during the H&E staining, and we never bothered to rehydrate a section with distilled water before going into the first staining solution.  If the section appeared to be lifting up (swells up) at some point in the staining protocol, a careful rinse then air dry with a stream of compressed air or use a hair dryer on cool setting. GMA is a bit more forgiving with this little trick. .  I would not air dry after removal from a stain solution but after a rinse.  A small fan or even a cool setting on small hand held hair dryer should work.  Forced air was our favorite since it put a stream of air at higher velocity againt the section, drying was instantly done when doing Giemsa's and after alcohol rinse steps.  

My apologies for a long lecture and good luck on retaining the GMA sections. 

Gayle M. Callis
Bozeman MT     

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