The Eppendorf Vacufuge Concentrator Model 5301 from Brinkmann is an integrated device for the vacuum evaporation of liquid samples in test tubes and microwell plates. In its complete version, the Concentrator has an integrated diaphragm vacuum pump, so that no additional equipment is necessary. It comes with a rotor that has a maximum capacity of 48 1.5 or 2.0 tubes but a 70-place rotor (for 1.5 and 2.0 tubes) as well as a 72-place rotor (for 0.5 ml tubes) are also available. Moreover, samples placed in two 96- or 384-well microtiterplates can be processed. There is also a heating option that can be set at 30
o, 45
o or 60
oC. Additionally, there are a number of special functions that facilitate the concentration of aqueous and alcoholic solutions.
One of the key features that we were looking for in a vacuum concentrator is a small footprint. Because the Eppendorf Concentrator has a built-in vacuum pump, it allows for a significant savings of lab space, especially in our tiny, instrumentation-only rooms. Yet, after a short time, we realized, that the concentrator has a number of features which made our sample preparation much more robust. The ability to elevate the temperature of the vacuum chamber significantly shortens the time of concentration of aqueous solutions (such as plasmid preparations). Another helpful feature is the special operation mode, used for evaporating solutions containing alcohol. We all know how difficult it is to find the balance between completely removing the ethanol from the precipitated DNA and complete dehydratation of the pellet making it insoluble. Using the Eppendorf Concentrator, it is possible to set a precise time period, usually several minutes, to get rid of the solvent traces. We use also frequently use the concentrator as a desiccator, since the chamber can be evacuated without rotor rotation. This is especially useful in cases where we are concentrating nucleic acids from large volumes (20-30 ml). After taking out the rotor, even 50 ml tubes can be placed in the chamber in an upright position.
The only drawback I noticed using the concentrator is that it is somewhat complicated to set the special functions (for aqueous and alcoholic solutions). There is no extra key for this purpose. Two other keys have to be pressed in order to activate the desired option. Also, there is a combination of blinking ventilation and vacuum control lamps that indicate the operation status – it takes some getting used to before one can quickly recognize what they mean.
Summarizing, my experience with the Eppendorf Vacuum Concentrator has been positive. Its broad spectrum of re-concentration options as well as its compact size will suit any molecular biology laboratory.
Michal Janitz, M.D.
Max Planck Institute for Molecular Genetics
Berlin, Germany