The current spin on centrifuges

Aug. 1, 2003
Centrifuges separate materials from solution by spinning the contents with inertial force, which pulls particles of varying density away from the center. Today, increasingly large numbers of categories of machines from ultra floor models to powerful mini table models to personal micro models to specialty machines are being offered. Many manufacturers have a range of products from a tiny two-tube unit for a small laboratory, to one that can meet the throughput needs of a large clinical lab. Speeds can normally be specified in rcf or rpm modes on most models. Industry trends have moved toward integration of the units into automated labs with less manual handling of samples, shorter spin times, and smaller sample and unit sizes to conserve valuable bench space. Most manufacturers carry a wide range of swinging-bucket and fixed-angle rotors and adapters to accept a multitude of tube sizes, shapes and holders. Here, an array of centrifuge products give a hint of what is currently in the marketplace.High throughput
From routine sample handling to specialized tasks, the SPINCHRON DLX centrifuge is designed for a wide range of diagnostic applications. The instrument features a brushless induction drive system for low maintenance and increased reliability, as well as a number of safety features, such as an imbalance detector that automatically shuts down the instrument if rotor loads are severely out of balance. A wide range of accessories is available, including rotors, canisters, sectors, microplate carriers and tube adapters. The DLX can spin entire sectors, whole racks and even microtiter plates.Beckman Coulter
The Eppendorf centrifuge model 5702 can hold 30 x 15-mL round-bottom tubes or 20 x 15-mL conical tubes. A swing-bucket rotor is available to spin four 85-mL tubes in aerosol-tight buckets at rcf up to 3,000 xg. For applications requiring higher tube capacity, rectangular buckets holding up to 24 15-mL glass tubes can be used. The maintenance-free drive is adjustable to speeds up to 4,400 rpm. The system features automatic soft-touch tube locking, quick acceleration/deceleration and optimized airflow to cool samples. A timer can be set to run up to 99 minutes, or for continuous run.Brinkmann Instruments performance
The EBA 21, with a variable, maintenance-free frequency drive, generates a maximum speed of 18,000 rpm. Users can enter runtime, short-cycle mode and nine braking and acceleration levels on the foil keypad in the units lid, where parameters are digitally displayed. Safety is provided by a metal housing, rotor detection, lid locking/emergency release and load imbalance shut-off. Ten interchangeable rotors enable many tube sizes and applications, from rcf 2.8 to 23.9. Three complete running programs can be microprocessor-stored and recalled for future use.Hettich Zentrifugen cytocentrifuge system
The Cytofuge2 cytocentrifuge is small (5.5 lb), compact and quiet. A covered leak-resistant rotor and chamber gasket help reduce exposure to biohazards. Optimum acceleration/braking rates for each speed setting are automatically microprocessor-controlled. A reliable, energy-efficient 24V motor produces virtually no heat. Unbreakable see-through cover and a high-strength chassis ensure mechanical containment and safe operation at all speeds. The cover pops open to signal cycle completion; the reliable latch is safe and convenient. Speed is within 5% of set condition.StatSpin or double ultracentrifuge
The Centrifuge automates the separation and sorting processes to reduce errors, protect workers from biohazard exposure and increase productivity. The system is available with a single or double centrifuge. Specimen container size can range from 12-mm to 16-mm diameter and 75-mm to 100-mm height. Specimens can be processed individually or in batch mode (one to 80 specimen containers). The Centrifuge integrates with the LAB-Manager Process Control software and the Transport System to help produce a complete pre-analytical automation system. Throughput with one robotic arm is up to 250 specimen containers per hour.LAB-Interlink and quiet
The Z300 and the Z300K refrigerated centrifuges accommodate tubes from 0.2 mL to 100 mL, in both swing-out and angle rotors. Fourteen rotor options allow the units to meet a variety of applications. Maximum rotor speed is 13,500 rpm. Brushless, induction drive motors provide smooth, quiet operation, and microprocessors control all operating parameters. Other features include automatic rotor recognition, overspeed protection and rotor imbalance detection. Acceleration/deceleration rates can be set to protect delicate samples. The Z300Ks refrigeration system maintains samples below 4C.Labnet International carbon fiber rotors
The FIBERFuge 3K tabletop centrifuge features FIBERLite carbon fiber technology, which replaces aluminum and titanium alloy rotors with corrosion-free, stronger, lighter and more durable carbon fiber rotors. FIBERLite rotors can be purchased separately for most popular models; each one ships with a factory-installed centrifuge-specific hub to make it fully compatible with the intended centrifuge. Rotors can be washed and soaked in a wide range of lab detergents, and are autoclavable. The system includes a 24-month unconditional warranty on the centrifuge and an unlimited lifetime warranty on the rotor.Piramoon Technologies serum volume
The LC6 horizontal centrifuge is designed to spin six blood tubes at a set speed. The system features an electronic timer for precise spin times from one to 30 minutes. The horizontal rotor design ensures uniform gel barriers for maximum serum volume, and the instruments brushless motor operates smoothly and quietly. Safety features include a clear lid for sample viewing and an automatic lock. Operating speed is 3,150 rpm at 1,465 x g. The company offers a full range of centrifuges from micros to benchtop models.Sarstedt micro
While 12″ x 23.2″, the system requires very little bench space, the Microlite ventilated microcentrifuge combines large sample capacity, a speed of 13,500 rpm at 17,000 x g and a quiet 62 dBa at full speed with a load of 24 x 2-mL samples, or 48 x 0.5-mL microtubes. The system features gentle and fast acceleration/braking speeds, audible end-of-run signal and momentary-spin and time-hold selections. The refrigerated Microlite RF model has most of the same system specifications; the Micromax provides up 21,000 x g. Rotors are interchangeable across all models.Thermo safety cabinet
The Cytopro cytocentrifuge standard rotor has an eight-slide capacity and advanced sample chamber design for exact alignment of the absorption pad. The rotor is autoclavable and can be loaded into a separate biological safety cabinet with airtight lid seals to contain biological hazards. The patented dual sample chambers are disposable or reusable and incorporate Cytopads to absorb cell suspension fluids; pad replacements with different absorption rates are available to match customer needs. The unit features simple, flexible programming, convenient pre-wetting capability and in situ fixation.Wescor Biomedical family
A complete range of rotors, tubes, bottles and accessories maximizes versatility in the Sorvall Discovery SE floor model ultracentrifuges and micro-ultracentrifuges. Both provide flexibility and functionality, with speeds up to 150,000 rpm, application-dependent. The Sorvall STEPSAVER and Surespin rotor systems allow faster and more secure loading and processing of samples. Standard features include a 20-program memory, low rotor k factors for faster separations, simple run parameter entry, a quick-setting rotor system and quiet operation (< 48 dBa). Systems are covered by a five-year, nonprorated drive warranty.Kendro Laboratory Fitzgerald is associate editor of
MLO. Daniel M. Baer, MD, in preparing this article.
August 2003: Vol. 35, No. 8
© 2003 Nelson Publishing, Inc. All rights reserved.

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