Appendix: Instruction Manual for Use of Vacuum Oven

May 14, 1990

Jim Howe

Description

The vacuum oven (Scientific Products Tempcon) is used in this lab for baking membranes after transfer of DNA. This allows for irreversible binding of the DNA to the membrane, contributing to the longer life of these filters. The temperature control is set from the lower front panel of the oven; we attempt to keep the temperature at approximately 80 degrees C. There are two valves controlling the level of vacuum in the oven, located on top of the oven. The one on the right is the vacuum release valve (which is open to the room), and to the left is the vacuum valve (hooked up to bench vacuum). Opening and closing the oven door are determined by the level of vacuum in the chamber (with full vacuum, the door can be closed, with full vacuum release the door can be opened). The pressure gauge for the chamber is located on the top of the apparatus.

Operating Instructions

Opening the oven door:

Turn vacuum valve completely clockwise, and vacuum release valve completely counter-clockwise. You will hear a hissing sound signifying the equilibration of the pressure in the oven chamber with the lab outside. As the sound diminishes, the oven door will open.

Closing the oven door:

Push the door closed and hold in place so that a seal is made with the door gasket and the oven chamber. Turn vacuum release valve completely in the clockwise direction, and the vacuum valve in the counter-clockwise direction. Hold seal until pressure rises above 15-20 mm Hg.

1. Apply vacuum grease to door gasket frequently.
2. Keep side and back vents clean of dust for maximum air circulation.
3. Clean up spills in oven as soon as possible after they occur to avoid having the material being baked on. Use a soft cloth and hot, soapy water when the oven is cool.