The idea behind the Eppendorf MiniSpin Plus was to create an inexpensive, small, quiet, robust centrifuge that could fill the role of traditional desktop centrifuges. Of course, the price of these units played a large part in our purchasing decision – they are relatively inexpensive when compared to many other similar units. The major factor in our purchase of these instruments, however, was the size and spin-up/spin-down speed. In our laboratory, the MiniSpin Plus has replaced other centrifuges for both high-speed centrifugation and also for quick pulse-spins. In this they have performed well and at the same time they occupy a much smaller bench-top area (22cm x 24cm – previously, we used a selection of other instruments). Another major benefit of these instruments is the fact that they are easily portable (approximately 4 kg including rotor) and has suction-cup feet to prevent accidental movement during use. We regularly move our equipment from lab to lab, and between ambient to warm rooms and ambient to cold rooms. The centrifuges have operated well under these conditions and we have not encountered any difficulties or problems associated with the changes in temperature or humidity.
The MiniSpin Plus has a single, aluminum fixed rotor which spins up to 14,000 x g and can accommodate up to 12 x 2mL (or smaller) tubes and a steel clip-on lid. We use our centrifuges primarily for experiments involving bacteria and therefore we require the ability to sterilise the rotors periodically. These instruments have an easy-to-remove rotor that can be autoclaved whenever required.
Similar to Eppendorf’s larger instruments, the MiniSpin Plus has been designed for ease of use and quiet operation. The soft-touch buttons and LCD interface are simple to navigate and the lid is motorized, requiring little pressure to close. These centrifuges are capable of timed runs (up to 99 minutes), infinite runs and pulse-spins. Because the rotor is extremely light, the spin-up and braking times are very short (approximately 10 seconds), particularly in comparison to many other similar instruments. We found this to be a great benefit as we use them as general centrifuges at each bench-space. Of course, these centrifuges take longer for pulse-spins than the small single-speed centrifuges that are available. We believe that this is balanced, however, by the increase versatility of the units as fully-featured centrifuges.
Although the centrifuge is not refrigerated, it is designed to avoid heating during long spins. Eppendorf claims that the temperature will rise by less than 12oC after 20 min at full speed. This is significantly less than several of our other instruments which heat up considerably after extended spins because of the larger motor and closer proximity to the rotor.
Scott Coutts
Graduate Student
Department of Microbiology
Monash University
Australia