North Carolina State University is a landGrant university and a constituent institution
of The University of North Carolina
Department of Wood and Paper Science
NC STATE UNIVERSITY
STANDARD OPERATING PROCEDURE (SOP)
Beckman J21C High Speed Refrigerated Centrifuge
Location:
3121 Pulp and Paper Labs
CAUTION
Not properly balancing samples in the centrifuge can result in personal injury and damage to the
equipment
Standard Operating Procedure
1) Weigh out samples in the high speed centrifuge tubes, located in the clear plastic container on the lab
bench, making sure that the tubes, lids, and the samples weigh the same amount (This is VERY
important, failing to do so will result in damage to the machine and possible people in the lab)
2) Open the centrifuge using the button on the left front panel and the lever on the top
3) Place the weighed samples in the rotor, evenly distributing the weight (i.e., samples of the same weight
across from each other)
4)
5)
6)
7)
Place the lid on the rotor, making sure that it is sealed properly
Close the centrifuge door using the lever on the top
Turn on the centrifuge using the toggle switch on the bottom left corner of the control panel
Set the desired RPM, make sure the sample tubes can be used at this RPM and DO NOT GO ABOVE
14,000 RPM!
8) Set the desired time by turning the dial past 30 minutes and then back to the desired time
9) Press the white button to start the centrifuge, it will light up when the centrifuge starts
10) Wait until the centrifuge has reached full speed to make sure the load is even distributed – if it is not,
the centrifuge will vibrate and make noises - stop the centrifuge immediately by turning the dial back
to zero, reweigh the samples to make them equal in weight, including the tube and the cap
11) Do not open the lid while the rotor is moving
12) The light will turn off once the rotor has stopped moving
13) Remove the lid of the rotor, remove the samples, and return the lid to the rotor
14) Close the centrifuge lid and turn off the power to the centrifuge
15) Remove samples from the tubes, clean , and return to the plastic bin