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Just Released: Electronic Pipettes That Enable Calibration By Weight (mg) As Well As By Volume (μL)
With A&D’s MPA series of single channel electronic pipettes, users can correct deviations in dispensing volume easily by themselves. The series is also unique in allowing dispensing based on the weight of the sample liquid instead of its volume.
Accuracy assured for everyone at all times
Obviously, one of the greatest benefits that electronic pipettes bring is the fact that the dispensed quantities will not vary with each individual. The high precision stepping motor automatically moving the piston up and down realizes uniform pipetting for both novice and expert alike, making the results of analyses always reliable.
Meanwhile, many researchers still have their pipettes inspected and calibrated by an outside facility – once a year, or perhaps twice a year, depending on their workplace policies. Even with electronic pipettes, this kind of practice bears the potential risk of compromising the validity of a year’s worth of data if, say, an annual calibration showed that they might have been using inaccurate pipettes all along.
The MPA series can solve this problem by allowing researchers to perform calibration at their own location whenever they want (patent pending). Deviations in dispensing volume, if any, can easily be corrected by directly inputting the actual dispensed volume measured using an analytical balance. (For this, A&D also offer pipette accuracy testers, which automatically perform mass-to-volume conversions.)
Since this function can also correct errors arising from tip characteristics, it is possible for researchers to use other manufacturers’
Calibration in a unit of weight (mg)
In addition to the volume (μL) calibration, the MPA series enable calibration and display based on the weight of the sample liquid (patent pending). With the pipette showing the dispensing amount in “mg” units, it becomes much simpler to handle liquids that need to be managed by weight, such as diluted solutions of solids or powders, as there is no hassle of density calculation.
Further, this method lets researchers control more precisely the dispensing amounts of high-viscosity liquids, which are prone to error with normal volume calibration that uses purified water as the test liquid. It is also possible to select the reverse operation or adjust the aspirating and dispensing speeds to improve accuracy when handling viscous samples. (The reverse operation first aspirates a volume larger than the set dispensing volume, delivers the correct amount, and then discards the excess.)
Freeing researchers from aching thumbs
Users of manual pipettes typically suffer a repetitive stress injury in the thumb. This is because operating a manual pipette requires holding out the thumb perpendicular to the hand and then pushing the plunger all the way down with a force of a few kilograms. Such irregular movement can easily hurt the thumb as it is repeated day in, day out.
In contrast, the key operation of an electronic pipette requires a force of only a few hundred grams for a stroke of minimum distance. Moreover, with the MPA series, the plunger can be controlled by pressing a key with the ball of the forefinger (like pulling a trigger), while maintaining all fingers in a natural, effortless grip. As a result, researchers can avoid not only repetitive stress injuries but also a decrease in efficiency due to fatigue.
In fact, A&D’s internal experiment verified that virtually no strain occurs at all after 3,000 repeated pipettings over a 5 hour period.
Advanced multiple dispensing function
The MPA series has two more functions distinctive of electronic pipettes that greatly reduce time, stress and error associated with certain pipetting tasks.
One is the “multiple dispensing” mode, in which the pipette dispenses one aspirated volume (e.g. 1200 μL) by multiple installments of a smaller volume (e.g. 100 μL x 12 times). This function is highly useful when researchers need to repeatedly deliver the same amount of sample into a microplate, etc.
With conventional electronic pipettes, the first installment of multiple dispensing was typically inaccurate due to a mechanical backlash that occurred when the operation switched from aspirating to dispensing. The MPA series automatically corrects this error by discharging a small amount of sample immediately after aspiration so that the piston is always set in the descending direction before the dispensing starts (patent pending).
The other is the “mixing” mode, in which the pipette executes a set number of aspirating-dispensing cycles (by approx. 2/3 of the set volume) to mix and homogenize different kinds of liquids in the receiving vessel with one key press. With a manual pipette, the same task is especially laborious and also difficult to perform correctly when the mixing volume is small (prone to produce air bubbles).
Practical and user-friendly industrial design
Besides the operation (plunger) key being set underneath the forefinger, there are other design features that make long hours of operation less tiresome. Specifically, the display section of the MPA series is made compact and located so that the center of gravity of the pipette weight is lowered and does not deviate from the axis of grip. This makes the device feel surprisingly lightweight, much counter to the often-heard complaint that electronic pipettes are too heavy.
Another frustration users would feel with previous electronic pipettes was that they were easily breakable by dropping – their LCD panels in particular – which would incur high costs in time and money for repair. As a countermeasure, the MPA series has padding set on the four corners of the head, increasing resistance to impacts from falls (patent pending). On top of this, the finger hook that rests on the middle finger is long and curved in such a way that the pipette will remain perched in the hand even when the grip is loosened.
Additional details can be found on the A&D website at http://www.aandd.jp/
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A&D Company, Limited, headquartered in Tokyo, take advantage of their world-class analog and digital signal processing technologies to produce a diverse array of laboratory and industrial measuring equipment. In particular, they are known as Japan’s top manufacturer of electronic weighing instruments ranging from ultrasensitive micro analytical balances to scales of several tons of capacity. Their innovations are always aimed at providing users with high practical utility and high value for the price. To find further information on A&D, visit http://www.aandd.jp/
Mr. Michihito Matsuura