Technical information

Centrifuge Standard Operating Procedure 1
1. INTRODUCTION
1.1 Purpose of the Standard Operating Procedure
This standard operating procedure (SOP) is NOT a substitute for training
and/or reading the appropriate manuals before use. All principle
investigators and supervisors must document that training has been
received by students and staff who will be using the centrifuge.
A list of authorized users will be kept by the Instrumentation Technician in
SR314A.
This SOP is intended to promote consistent and safe use of the Beckman
Avanti® J30I centrifuge within the Faculty of Science. This SOP covers the
potential hazards, personal protection requirements, spill and accident
procedures, waste disposal considerations, and instrument operation for the
Beckman Avanti J30I centrifuge [henceforth referred to simply as the
centrifuge].
1.2 Centrifugation Theory
The following centrifugation theory is summarized from the Basics of
Centrifugation, Cole Parmer Technical Library.
The primary objective of centrifugation is to accelerate the rate of
sedimentation in a sample. Under normal gravitational forces, particles in
solution will gradually settle based on density, size, and mass. For dense
particles like small pebbles this happens very quickly; however, for very small
particles, such as cellular organelles or macromolecules like DNA and RNA,
settling by gravity happens far too slowly to be useful. A centrifuge is therefore
used to accelerate settling by spinning samples and creating forces that are
over 500,000x times stronger than gravity (e.g. 500,000 x g is called the
“relative centrifugal force”).
Centrifugation can be used for a variety of applications, including pelleting,
purification of cellular components, and density gradient separations. Pelleting
simply creates a hard-packed concentration of particles at the bottom or along
the side of a tube. Pelleting efficiency (k) is a measure of the time it takes to
pellet a given sample in a specific rotor, so rotors with a lower “k” will pellet a
sample in a shorter time. To compare pelleting time between two different
rotors, use the following formula: