Heat set: why and when?

[Maryfox]

I've seen many references to heating slides, but no info on why to do this or when to do this. I need to be educated.
Thanks,
Mary

[BramHuntingNematodes]

The ribbon fresh come off the 'tome is wrinkly even when you have a sharp knife, so heating a slide to just below the melting point of the wax will help smooth it. Sometimes this done with warm water.

There are microwave methods that increase the kinetics of some staining or fixative reactions with heat.

Smears when heated become semi-permanent.

[Jerradin]

It depends what you're doing. One reason to heat-set is that stains often need to be rinsed, either because they'll be too difficult to see through or because you want to apply a counterstain afterward. If you're staining a small sample, it's likely to be washed away.

[Element 56]

Are you talking about blank slides or complete mounts? Heating will speed up curing some mounting mediums. I sometimes heat Canada Balsam and Hoyers. A properly vented oven is of course necessary.

[Maryfox]

Thanks for your replies.
Unlike most of you, I am currently enthralled with chemicals rather than microbes. Techniques may be different. The images may be blah, interesting, beautiful, spectacular, or just weird.

boric acid peroxide pol 4x - reduced.jpg (52.9 KiB) Viewed 3205 times

[Element 56]

Some of my better crystals were grown in my fume hood which is room temperature. I just left them sit over the weekend or longer. Monitor the change over time is interesting. If you don't have a properly vented and or explosion proof oven you could just use a toaster oven outside. You can add a digital thermocouple for better heat control.

I rarely used a cover glass for mine. Just observe, clean and repeat. It's fun but I never got into any serious study so it kind of fizzled out for me. I did like working with different detergents. Dawn is good but the best I ever found was Alconox Keylajet. Eye drops that contain Tetrahydrozoline are a lot of fun too. It quickly crystalizes at room temperature so you can watch it happen under the microscope. Every now and then I would breath on the slide to repeat crystalization.

Have fun!

Kirby