The Swiss-made Socorex Calibra® “micro” pipette collection consists of 6 single channel, variable volume micropipettes with volumes ranging from 0.2 ul to 1000 ul. The Calibra® range is autoclavable at 121ºC while fully assembled; the microtip holder on the 2 ul and 10 ul models can be sterilized by flaming.
The whole of the Calibra® range features a “twin cam solid calibration system”. This system reportedly provides high accuracy and long-term stability in the calibration of the pipette. Published specifications for Calibra® pipettes report inaccuracies of <±0.7% to <±2.0% at the pipette’s minimum volume and ±0.5% to ±1.0% at the pipette’s maximum volume, with the exception of the 2 ul pipette specifications which are listed as <±6.0% and ±2.0% respectively. These specifications are comparable to those published by rival companies. I have found these pipettes, as advertised, to be accurate and to rarely need calibration. On the odd occasion that our pipettes have needed to be calibrated, I have found them to be no more difficult to calibrate than other brands.
Socorex Calibra® pipettes are strong while remaining relatively lightweight; they tend to fit in the hand nicely. The plunger is a good length which provides for smooth action, but without being overly long and difficult to reach. The volume display is relatively large and easy to read. The only real problem I have with these pipettes is the tip ejector button. The tip ejector button on these pipettes has a square shape and the edge of the button has a tendency to rub the inside of the thumb which can make extended use of these pipettes mildly uncomfortable.
The single biggest strength of this range of pipettes is the method employed to change the volume. Volume adjustment is achieved via the setting wheel, rather than by winding the plunger as in other brands. To adjust the volume of a Socorex Calibra® pipette, the plunger needs to be depressed and turned to lock it down. The upper number of the required volume can then be selected by rotating the setting wheel, which is located at the base of the plunger, e.g. if the desired volume is 65 ul rotate the wheel until “6” appears. The setting wheel can then be pulled upwards and rotated to change the lower number of the desired volume. Changing volumes on this system is significantly quicker than on the winding-type pipettes, particularly for large volume changes. Furthermore, this system ensures that once a volume is set, it is difficult to accidentally change it. The ease and speed at which volumes can be changed on these pipettes makes them the pipette of choice for applications which require regular volume changes.
Overall, I have found these pipettes to be easy to use, reasonably priced, reliable and well suited for general laboratory use.
Gabriel Milinovich
Senior Research Technician
University of Queensland
School of Veterinary Science