Elvanol Protocol

Elvanol (Polyvinyl Alcohol; PVA) is a polymer that penetrates the tissue and is used as a mounting media to firmly affix sections to the slide. To be used almost exclusively for mounting Nissls.

To prepare the PVA stock solution:

• Heat 1 L DI to near boiling (± 90º C) in the fume hood. Cover to prevent excessive evaporation. Use a thermometer to monitor temperature. If the DI boils, remove from heat and allow to cool.
• Remove from heat and gradually add 3.0 g PVA (Type II, Sigma #P1763) while stirring. Note: PVA dissolves slowly, taking as long as 30 min to go in solution.
• Add 1 g Na Azide* as a preservative. Note: This step is optional but especially useful if recycling/reusing the PVA.
• Let solution cool to RT, filter if needed and store at 4ºC

Mounting:

To mount, transfer sections to 6-well trays containing PVA, then mount as normal using PVA in place of buffer in the petri dish. No post-processing or rinsing needed. As for all other mounting, place mounted slides in racks and store racks in the drying oven until ready to stain.

Note: After mounting, PVA can be filtered and reused. Store filtered/recycled PVA in a separate stock bottle.


*Na Azide is toxic (works like CO, irreversibly binding to haemoglobin). Always were mask and gloves. It does not need to be weighed in the hood, but care should be taken to clean the balance and counter whenever and wherever Na Azide is used. Once in solution, gloves nor mask are needed while mounting.