Preparation of biological samples for analysis
There are many pieces of equipment that are used to prepare biological samples for analysis.
A. Sorvall-type centrifuge –A Sorvall-type centrifuge, or preparativecentrifuge, has a balanced rotor that holds vessels and spins them at high speed, up to 20,000 rpm. This will cause most insoluble particles such as cells and many subcellular components to rapidly form a pellet at the bottom of the vessel. Rotors are available that hold vessels as small as a few milliliters to as large as a liter. These centrifuges are often refrigerated so that heat-sensitive compounds are not damaged during centrifugation. We do not have one of these in our lab.
B. Tabletop centrifuge –A tabletop, or clinical, centrifuge is generallynot refrigerated and spins at a much slower speed than a preparative centrifuge. Rotors for clinical centrifuges generally hold tubes with a capacity of 15 mL or less.
C. Microcentrifuge –A microcentrifuge holds microcentrifuge tubesthat can hold about 1.5 mL of liquid. These microcentrifuges can also spin at high speeds and are sometimes refrigerated.
D. Sonicator –A sonicator emits ultrasonic waves that can be used to