Dear Clarissa,

Suppliers of Hoyers are are rare and also seem to come and go, and it can therefore be hard to get a supplier. I imagine you've found the Hempstead Halide product, which you might get sent to Malaysia if you go via EBay. See:

https://www.ebay.com/itm/Hoyers-Microscope-Slide-Mounting-Medium-30ml-/112608190768?&shqty=1&isGTR=1#shId

Shipping to Malaysia isn't cheap, but might be your only option.

I have never used this product so I cannot give my opinion on it. Other acarologists make it themselves providing they can get chloral hydrate, which is difficult to get because it is often restricted, while others try alternatives to Hoyers. Ready-made PVA is more commonly available and may be a suitable alternative.

Kind regards, Owen.

Hi Clarissa and Owen,

As Owen mentioned, you can hardly find it online. I usually prepare it by myself following Zhang (2003). It is not that difficult. As chloral hydrate quite restricted being toxic, you can provide the supplier/company an official letter from your institute that declares 'for scientific purposes only'. Another obstacle is getting the Arabic gum in crystal form (preferable than powder form). If I made a short visit to my home country Egypt, I can ship you some.

All the best,

Mohamed

To everyone who might be interested...

I don't know how much this information will be helpful to you but you can also use Faure's medium and prepare it yourself (like we do this in our department). The recipe can be found in: Krantz G.W., Walter D.E. 2009. A manual of acarology.

Best regards,

Hanna.

Amazon.com has this product listed: Under Hoyer Mounting Medium

Hoyer's Microscope Slide Mounting Medium (10ml) See all 4 in this Product Family

https://www.amazon.com/Hoyers-Microscope-Slide-Mounting-Medium/dp/B075FFX517/ref=sr_1_fkmrnull_2?crid=1Z11XWH3F0CJF&keywords=hoyer+mounting+medium&qid=1556310188&s=gateway&sprefix=Hoyer+moun%2Caps%2C190&sr=8-2-fkmrnull

why not make up by yourself？ it is not difficult

Or you can use polyvinyl alcohol medium (PVA) which is optically superior to Hoyer's medium (the refractive index is closer to that of the glass of the microscope lens, so fewer chromatic aberrations) and easier to use (it does'nt require ringing of the coverslip to prevent shrinkage; dissolves in water, so easy to remount specimens). It also avoids the use of chloral hydrate, which is a controlled drug in many countries, and gum arabic, which is increasingly hard to obtain in really good quality. PVA mounting medium is available commercially or you can make your own.

You can prepare Hoyer medium by follow

Hoyer’s mediun contains 50 mL distilled water, 30 g Crystalline gum arabic (or gum acacia), 200 g Chloral hydrate, 20 mL Glycerin (Krantz et al., 2009).

Krantz, G.W., Water D.E., Behan-Pelletier, V., Cook, D.R., Harvey, M.S., Keirans, J.E., Krantz, G.W., Lindquist, E.E., Norton, R.A., OConnor, B.M., & Smith, I.M. A manual of acarology (G. W. Krantz & Water D.E. Eds.). USA: Texas Tech University Press. 2009, ISBN-13: 978-0896726208

Thank you everyone for your answers. I have decided to prepare Hoyer's medium on my own. Many thanks for all the thoughtful suggestions.

What will be the concentration of Poly Vinyl alcohol (PVA) used in Hoyers media in place of Chloral Hydrate?