Visikol and Hoyer's Solution, I receive this information from Tom Villani , and chemist expert:  "To prepare the samples, typically we soak in Visikol for 20-30 mins (small specimens prepared right on slide), sometimes overnight for large samples. Gentle heating on a hotplate will help remove bubbles and speed up penetration of Visikol into the specimen. At that point, if desired, adding arabic gum dissolved in water to the cleared sample containing Visikol and mount. We typically use 1:1 volume of Visikol : saturated arabic gum solution." This information comes from Tom Villani.    He is doing studying the situation.   Hoyer still for me the best media, as long as you ring with a glyptal or a similar product the cover slide.  Furthermore,  as soon as  your mounted mite specimens are dry and ready for  study, take (600 to 1200 dpi) photos in DIC and Phase contrast (40 - 100X), and safe the images in association with your specimen.   

Hello,

for mounting fleas, our lab is using canada balsam, air bubble is forming at the moment of mounting but they are resorbed after some hours. 

Do you isolate the hoyers from the sides with anything? Applying glyptal or even nail polish may help. But maybe I understood the problem incorrectly...

Dear Mahran,

The following discussion is still useful:

http://www.nhm.ac.uk/hosted-sites/acarology/archive/summary.html

There are alternatives, but there is still no perfect media, especially for delicate small mites. I still use Hoyer's because (a) it's easy to use; (b) I know I can remount spoiled slides and thereby 'rescue' specimens for future study. I have experimented with PVA (a disaster, but others like it) and DMHF. The latter showed some promise , but it does not clear after mounting and is horribly sticky to use - but I think it's worth experimenting with it further.

Kind regards, Owen.

Visikol and Hoyer's Solution, I receive this information from Tom Villani , and chemist expert:  "To prepare the samples, typically we soak in Visikol for 20-30 mins (small specimens prepared right on slide), sometimes overnight for large samples. Gentle heating on a hotplate will help remove bubbles and speed up penetration of Visikol into the specimen. At that point, if desired, adding arabic gum dissolved in water to the cleared sample containing Visikol and mount. We typically use 1:1 volume of Visikol : saturated arabic gum solution." This information comes from Tom Villani.    He is doing studying the situation.   Hoyer still for me the best media, as long as you ring with a glyptal or a similar product the cover slide.  Furthermore,  as soon as  your mounted mite specimens are dry and ready for  study, take (600 to 1200 dpi) photos in DIC and Phase contrast (40 - 100X), and safe the images in association with your specimen.   

thanks for all Scientists who responded to my  question about disaster problem which i am facing even i am following stander sequence of work and nail polish also applied to isolate medium from outside effect. for that i started adopting imaging idea which Dr. Ochoa pointed out for important characters like male aedeagus and tarsus of Tetranychidae on which i am working.

I have been using Euparal for a while without problems, suggest to try that (but beware of the different qualities of that medium on market) !

Thank you, Kaarel Sammet  i started reading about Euparal. Sir, Baharudin Omar, problem of bubble will start after six to one year not during mounting of mites specimens, we did have doubt about quality of medium, but still we have same problem with newly prepared  medium. 

Are the air bubbles there from the moment you mount them? If so, it suggests you are placing the coverslip directly face down on the hoyers mountant. Don't do that if you can avoid it. Tilt the coverslip onto the hoyers mountant very slowly so that it allows the air bubbles to be gently pushed away. The coverslip should begin at around a 45 degree angle and should be tilted until it is flat against the hoyers. May be you already knew this. I just thought that this may be your problem.

Dear colleagues,

Here's another paper that's worth reading on the topic:

Brown, P.A. (1997) A Review of Techniques Used in the Preparation, Curation and Conservation of Microscope Slides at the Natural History Museum, London.

The Biology Curator, Issue 10 Special Supplement, pages 1 - 34.

http://www.natsca.org/article/455

All acarologists should expect that slides in Hoyer's will spoil sooner or later, so exploring other media is a worthwhile pursuit. As Hoyer's is hygroscopic, the more humid the environment the faster they spoil. Mahran, I presume your slides are kept in a controlled environment, but perhaps it's worth checking humidity levels.

For those with the luxury of time (or technicians) to prepare Canada Balsam specimens, see: Saito et al. (1993) A method for preparing permanent specimens of mites with Canada balsam. Applied Entomology and Zoology, 28:593-597. Mounting a back-up type specimen in a permanent medium is a very good idea, and Canada Balsam is arguably the most tried and tested permanent mount.

Kind regards, Owen.

I use modified Dionis mountant if RI is important (as in Acari) or Eupral/CB/Gum Damar if not