Appendix: Using the L8M-80M Ultracentrifuge

June 26, 1990

Matthew S. Holt

  1. Locate power toggle and flip up to on position.
  2. Verify key position (immediately to the left of the power toggle) for the rotor which you wish to use. Place rotor in centrifuge. NOTE: each rotor has a maximum speed coded into its name (e.g., VTi80 has a maximum speed of 80,000 rpm and should not be used above 75,000 rpm; SW28 should not exceed 25,000 rpm). Refer to the rotor manual if in doubt.
  3. Activate the vacuum by pressing the VAC key (NOTE: each parameter key has a light in its upper left corner that will blink until the set parameter is acheived).
  4. Program desired speed by pressing the SPEED key and entering the correct rpm on the keyboard and then pressing the ENTER/DISPLAY key. (NOTE: when a parameter key is pressed, the display at the top for that paramter will start blinking. You have approximately 5 seconds to enter the parameter before the display changes to the actual reading of all parameters, at which time the ultracentrifuge will not accept programming. This is true for all parameters except vacuum.)
  5. Program the desired temperature setting by pressing the TEMP key and entering the correct temperature on the keyboard and then pressing the ENTER/DISPLAY key.
  6. Program the desired time by pressing the TIME key and entering the correct time on the keyboard and then pressing the ENTER/DISPLAY key.
  7. Acceleration and deceleration settings are different for each rotor and particular applications. Swinging bucket rotors (SW) must have ACC 1 and DEC 1 settings. 1 is the fastest and 9 is the slowest. Gradient spins should have DEC 9 settings to maintain the gradients. To set the acceleration and deceleration rates, first press the w[2]t key, then press the ACC key followed by the desired acceleration rate on the keyboard and then the ENTER/DISPLAY key, and then the DEC key and its rate followed by the ENTER/DISPLAY key.
  8. Once all parameters have been set, press the START key. Again, you have approximately 5 seconds once the last parameter is set before the display changes to an actual reading, at which time the ultracentrifuge will not start.
  9. You may elect to activate the hold by pressing the HOLD key followed by the ENTER/DISPLAY key. The ultracentrifuge will maintain the set parameters and will only decelerate when the user presses the STOP key. Otherwise it will decelerate when the time parameter has expired. The time display will count up in hold position and count down if the hold is not activated.
  10. Fill in the log book for each run indicating date, rotor type, rotor serial number, speed, time, and revolution counter reading (located on the bottom left of the display board).
  11. Some rotors will not spin faster than 2000 rpm until a certain vacuum is achieved.
  12. The vacuum cannot be released until the rotor speed has fallen to less than 2000 rpm.
  13. Always shut off the ultracentrifuge when finished and return the rotor to the cold room.