Frequently Asked Questions

Frequently Asked Questions

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Adjusting the radius is important when you need to exactly reproduce protocols to ensure accurate results. Conversion from speed (rpm) to g-force (is based on the biggest (rmax) radius of the rotor. If you are using an adapter for tubes, correct the radius-value if possible at the centrifuge.
Eppendorf kit rotors (which typically differ from other manufacturers’ kit rotors) also feature greater distance between the rotor bores, which makes loading and unloading the rotor very convenient. In addition, this greater distance can prove especially helpful when working with long spin columns (e.g., those from Princeton Separations) as you can fully load the rotor and use the rotor’s entire capacity.
Some nucleic acid purification kits with spin columns that are produced by certain manufacturers sometimes don’t allow you to close the tube lids when you’re working. This means you have to centrifuge with open tube lids. These tube lids might rip off during the stress of centrifugation and damage the rotor/rotor chamber. The kit rotor with a raised rotor rim was designed to avoid this problem. Open tube lids are supported by the rim will not rip off during centrifugation. 
Some centrifuge manufacturers provide special coated rotors in addition to their standard rotors. In Eppendorf’s centrifuges, the special coating provides enhanced chemical resistance to phenol, acetonitrile, DMSO, acetone, trichloroacetic acid, acetic acid, and sodium hypochlorite, due to a polytetrafluoroethylene (PTFE) coating applied over the actual anodic coating. Please note that coated rotors from other manufacturers may have different properties.

To be able to centrifuge samples at the desired temperature right away, the user can start a temperature precool run by pressing the “precool” key and go on to prepare their samples during the run.

Yes, this is possible, as long as the rotor is loaded in a symmetrical fashion, with the 15 mL tubes loaded opposite 15 mL tubes, and the 50 mL tubes loaded opposite 50 mL tubes, respectively. Please be sure to use suitable adapters.

The conversion of speed (rpm) to g-force (rcf) is based on the largest radius of the rotor. In case an adapter is used to accommodate centrifuge tubes or vessels, the value of the resulting specific radius can often be selected manually. The specific radii of each respective adapter are listed in the technical specifications of the rotor. The adjustment of the radius is especially important if exact protocol reproduction is required in order to ensure accurate results.
Buckets must be loaded symmetrically in such a way that all respective rotor pegs are burdened equally. This is best achieved by loading around the center of gravity of the bucket. Ensure that the buckets are able to swing out freely at all times by performing a manual swing test. Buckets should always be able to swing out correctly without the load touching the rotor cross or the rotor chamber.
Rotors, buckets, sleeves and adapters should be cleaned on a monthly basis using a neutral cleaner in order to prevent changes in the material caused by residues from centrifuged liquids. Please do not, under any circumstances, use sodium hypochlorite/chlorine-containing or oxidizing disinfectants or cleaners. Disinfection using glutaraldehyde solution is an option. We recommend Cidex® activated glutaraldehyde solution (®: Johnson & Johnson, USA). Plastic adapters and rubber inserts are dishwasher safe.
The coating offers improved chemical resistance to phenol, acetonitrile, DMSO, acetone, trichloroacetic acid, acetic acid and sodium hypochlorite. It is a PTFE coating which was applied to the actual anodized layer. Due to the material properties of this coating, autoclaving (121 °C, 20 minutes) improves the chemical resistance of the rotor.
One advantage of centrifugation in the swing-out rotor is the sedimentation of molecules that cannot be pelleted using a fixed-angle rotor (microgradient, e.g. blood/Ficoll).

Aerosol-tight rotors are always recommended when working with dangerous or potentially dangerous substances. These can include, for example, viruses, pathogenic bacteria, potentially infectious blood samples or radioactive sample material.

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