Technical information

Centrifuge Standard Operating Procedure 7
2. POTENTIAL HAZARDS
NEVER CENTRIFUGE MATERIALS THAT ARE CAPABLE OF DEVELOPING
FLAMMABLE OR EXPLOSIVE VAPOURS.
DO NOT CENTRIFUGE RADIOACTIVE, PATHOGENIC, OR TOXIC SUBSTANCES IN
THIS CENTRIFUGE.
Centrifuges have the capacity to be VERY dangerous, and care must be used
each time a run is set up. Do not bump, lean on, or attempt to move the
ultracentrifuge while it is running.
Tubes and bottles must be inspected before each use to make sure that they
are in excellent condition, and it must be verified that the tubes in use can
withstand the g-force generated by the run conditions selected; small scratches
in glass or polycarbonate tubes can cause failure at high g-forces, resulting in
the loss of the sample, an imbalanced rotor, and potential damage to the
ultracentrifuge. Tubes may display crazing: small cracks that do not penetrate
all the way through the wall, but if a crack approaches the outer wall of the
tube, discard it. Do not use a tube that has been come yellow or brittle with
age. A tube may fail if it is not the correct shape, or if an incompatible
solvent/tube-material combination is used. It is recommended that only tubes
specifically designed for this ultracentrifuge and a given rotor be used. Use
of other tubes may void the instrument and rotor warranties.
Use only the rotors listed in Table 1-3 in the Avanti J30I centrifuge. Rotors
should never be run empty; at least two filled tubes should be run in the
rotor, even if they are just water filled blanks during a rotor cooling run. Do
not attempt to set the speed higher than the maximum rated speed of the
rotor in use. NEVER attempt to stop a rotor by hand or open the door while the
ultracentrifuge is running. DO NOT USE any sharp tools on the rotors as this
will lead to scratching and corrosion.
Samples MUST be run balanced, both in position and individual mass. This
can be accomplished by opposing two equal weight tubes/bottles on opposite
sides of the rotor. Equal weight must be determined including tube closures
using the pan balance or an electronic balance; balance tubes to within 1
gram. Rotor balance can also be obtained by equally-spacing an odd number of
tubes around the rotor (see Figure 2-1). If you only have one sample, you must
use a second tube/bottle containing a liquid with a similar density and ensure
that the weights/volumes of the two vessels are the same. The ultracentrifuge
has an imbalance detector, and will automatically end the run if a rotor is out
of balance. However, serious damage may have already occurred, so DO NOT
rely on the imbalance sensor to stop the rotor if you load imbalanced samples.