Either you make section using cryo-preservation sectioning method, or you may go the conventional preservation technique, In Drosophila, we made conventional technique. It works well. 

Thank you Sir. Can you please give me your protocol?

Brain diissection  (4°C) immediately after

Fixation (Paraformaldéhyde 4% poids/volume dans du PBS 0.1M) 1h-1.5h ,

Cryoprotection in  sucrose (saccharose à 30% masse/volume dans du PBS0.1M) or 15% then 30% overnight 4°C.

Put 3 brains on a slide (Super Frost Plus),  eliminate  sucrose with absorbant paper ,

Embade each brain  in Tissue Teck.

Put the slide on the vapors of liquid nitrogen at -40°C. All turn solid and white

When you hear "click" , it is OK

Put quickly the slide in microtome (Leica CM 1800) at -20°C,  wait 10 min for temperature equilibrium before fixing a brain on holder

avoid thawing the brain when fixing on the holder with Tissue Teck.

we performed sections of 10 or 20 microns

avoid using sections just after sectioning, they can be not enough fixed .

Good luck

Catherine

Thank you so much! I have been going crazy trying to figure out how to make cross sections of the bee brains. How are you? The results of Fyssen not out yet. But the good part is I have been awarded with the PhD degree. Hope you, Prof. Giurfa and the rest in lab are doing well.

Regards,

Priya  ..

I am greatly appreciating for detailing of my answer by the other scientists  in the network and to identify the flaws in the two methods. I appreciate the co-operation by the scientists. With best regards.  Rabindra Nath Chatterjee 

Thank you Dr. Mitra for this. If I stain with Bouin's will I lose the fluorescence? I need to view the section under confocal microscope.

Whole heads are critical to cut, because the chitin is very hard. Often it tends to lose the contact to the paraffin and produce scratches in the sections

Exactly the problem we are facing is with chitin! Often the brain does not come out in form of sections. It is just the chitin layer which is cross sectioned.