French Press
Revision as of 16:14, 6 May 2009 by Jpecherer (Talk | contribs) (Changes to protocol based on the non-functionality of the sample loading aparatus. More specific information on loading the cylinder into the French Press added.)
Prepare the Cell (Not Auto-Fill)
- Pour in sample, replace base and place back on the press. Ensure valves are tightened
Loading Sample
- Set French Press to Down and start. Pour sample into cylinder followed by the piston.
- Ensure that the piston is lubricated with glycerol.
- Place cylinder with piston into the French Press instrument from the back, making sure that the piston's lever is orthogonal to the brace screws.
- Position the valves such that they are accessible to your hands.
Lysing Sample
- For bacteria 15 000 psi of cell pressure is sufficient. For a 1cm cell this corresponds to about 1100 psi on the gauge (see chart)
- Turn black knob all the way to the left
- Set Press to High and ensure both valves are securely closed
- Start the press. The cell will move until it encounters pressure and will stop moving (the motor will still be running)
- Slowly turn the knob until the gauge pressure reads desired pressure
- Slowly open valve until sample comes out, keep an eye on the pressure and make sure it doesn’t drop. Continue until piston is fully depressed. Close bottom valve
- Reload sample if necessary
Cleaning/Storage
- Disassemble and rinse all parts with 70% ethanol then distilled water
- Normally cells are stored at 4C to reduce sample heating