|
|
|
|
Ethanol fix
If you don't remember how to prepare and dilute solution go here Preparation: (for 1 liter)1) Prepare 95% Ethanol solution. Ethanol can be bought at a concentration of 100% percent, which is called anhydrous or denatured. In this case it has to be diluted to 95%. It can also be obtained at 95%. 95% is the highest concentration that ethanol can be destilled to. To make it completely free of water a chemical process is used that may add traces of chemicals to it. So the best is to simply get destilled ethanol. It is also much cheaper. 2) Cool it to about 0oC (placing it in ice water is the most effective way) 3) Rinse your preparation a few times with this ethanol solution and then leave it on ice for 1-2 hours. Depending on the thickness of the tissue. For STGs it seems to work OK if fixed for 1 hour. If you leave it on ice, make sure that the ice is wet so that the temperature will indeed be kept at ~0oC, but make sure that your dish does not sink into the ice (which may happen if you are using the dissection Petri dish for this). 4) Rinse 2-3 times every 60 minutes in phosphate buffer + Triton X (if you are proceeding with immunostaining) or plain phosphate buffer if you are doing somthing else Keep your Ethanol solution sealed to prevent Ethanol evaporation. Since Ethanol and water evaporate at different rates, the EtOH concentration can change quite a bit. The tissue becomes white and hard in EtOH but becomes translucent and soft again when washed in phosphate buffer. It tends to stick to the walls of the plastic containers, etc. much more than when using aldehide fixes. Note 1) ALWAYS put the date on a freshly made solution. Also add your initials and concentration. 2) With this particular fix, you can use your standard physiology dishes and tools. EtOH evaporates and and very low concentrations is completely harmless. |
|
|
