May 21, 2013 by Kevin Keras
Most labs have used floor mount or bench top centrifuges for separation based assays for decades. Whether spinning samples to remove air bubbles, spinning down cellular debris or isolating supernatent, there are numerous manual access centrifuges on the market, but when it comes to automation, the choices are limited.
For a number of years, Agilent (formerly Velocity11) has offered the compact VSpin. VSpin has a two position rotor with buckets for std microplates. It can spin up to 300o rpm/ 1000g and has an automated door that allows direct access to plates using an offset robot gripper. Units can be stacked on top of each other for increased use of vertical workspace. The Optional Access2 loader can also grab the plate and present it externally to a liquid handler gripper or top loading plate mover like Twister2 or KiNEDx.
Hettich also provides a larger unit called the Rotanta 460 which can accommodate 4 plates at speeds up to 6200prm, but is a bit more of a challenge to integrate as the robot gripper fingers need to reach into the unit from the top. I have seen this done with Mitsubishi and Staubli robots and Tecan actually integrates this unit under an EVO liquid handler accessible via an open locator in the deck.
Sias’s Ixion is a compact unit, similar in size to the VSpin, however plate access (total of two) is through the top just like the Rotanta and can spin up to 2000rpm. This unit integrates nicely with Sias’ Xantus liquid handlers.
Finally, BioNex offers the HiG centrifuge which can also spin two plates. The bright orange color makes this unit hard to ignore…and a closer look shows that this unit may be the best of the bunch. With an automated lid that retracts from the top, the HiG does not need a plate loader like the VSpin as plates can be accessed by just about any robot gripper. At 5000g, BioNex claims this unit to be the fastest robot accessible centrifuge available.
Maintenance requirements for each of these devices is similar. All include high-speed motors so proper ventilation is a must. Bearings must be greased, sensors cleaned and pneumatics (door opening, plate loaders) checked for leaks. Additionally, rotors and buckets should be checked for cracks or other signs of wear. As noted in previous blogs, rotational speeds can be verified using a digital tachometer but you may need to remove covers to gain access to the rotor (kids, don’t try this at home…call a professional). As always, if you ignore that last piece of advice, don’t come crying to me when your friends make fun of you because you have a mircrotitre plate permanently embedded in your cheek…