Protargol : silver impregnation of ciliates

Protos · Post by **Protos** » Thu May 08, 2014 2:23 pm

I am getting back to this nice technique to identify ciliates using silver impregnation. There is space for improvement but it's getting interesting
Stylonychia sp

Oxytricha sp. (TBC need more info on mid ventral cirri)

Beatsy · Post by **Beatsy** » Thu May 08, 2014 4:56 pm

Yes, very interesting! Can you describe more about the technique you used ? Are the ciliates still alive in these images or does the staining protocol kill them? Cheers. Beats.

Protos · Post by **Protos** » Thu May 08, 2014 9:58 pm

In order to identify ciliates and for taxonomic evaluation, silver impregnation techniques are almost indispensable. The methods that are most frequently used are the dry and wet silver nitrate impregnation methods from Klein Chatton-Lwoff, the silver carbonate staining method from Fernandez-Galiano (which I use also see some of my posts) and the protargol impregnation methods by Dragesco, Deroux and Tuffrau. First discovered by the French school it is now improved by many including Foissner.
The methods I use here include about 30 steps which main parts are:
fixing ciliates with Boin
mounting them in glycerol albumin on a slide
Clarifying ciliates with K permanganate and oxalic acid treatment
staining with silver proteinate at 60°C
stopping impregnation with sodium hyposulfite
finally dehydrating and mounting in Balsam.

A slightly better view from below

Beatsy · Post by **Beatsy** » Fri May 09, 2014 2:45 am

Thanks for the info. Not a simple process then - congratulations on your excellent results. Particularly impressed that you end up with permanent mounts that are surprisingly well preserved. Very cool.

Bruce Taylor · Post by **Bruce Taylor** » Fri May 09, 2014 11:04 am

Wonderful!

Do you have a commercial supplier for the protargol, or did you synthesize your own?

Jean-marc · Post by **Jean-marc** » Fri May 09, 2014 2:07 pm

Congratulation Protos, it is very good.

JM

Protos · Post by **Protos** » Sat May 10, 2014 12:29 am

Bruce Taylor wrote:Wonderful!

Do you have a commercial supplier for the protargol, or did you synthesize your own?

I had some old protargol left, it works well at 0.4%
The protargol from Sigma works at 1% but not as strong
I will try to synthesize it according to the published recipe.

I will continue to use Silver carbonate for non-hypotrich ciliates; results are better and it is less time consuming !

Here comes a pic at 100x oil