Mechanical micropipette: The ultra light pipette that delights your hand.The Eppendorf Research plus mechanical pipette combines about 60 years of innovation in liquid handling and is one of the most commonly used pipettes in the world. It provides you with one of the safest and most ergonomic pipettes available today. The Research plus microliter pipette protects the health of our customers during their daily work in the laboratory. A premium pipette that delivers extraordinary precision and accuracy. The Eppendorf Reference 2 mechanical air-cushion pipette with outstanding precision and accuracy is extremely reliable and robust, allowing for a long service life. With its unique single-button operation, the Reference 2 provides fast and ergonomic handling with reduced operating efforts and active aerosol reduction. The clear haptic feedback helps to avoid accidental tip ejection.
Calculate the pipette volume as per following formula given below Volume = (Weight of Purified Water) / D Calibration of Fixed Volume Micropipettes Attach a disposable tip and pre-rinse the tip. Set the desired or lowest volume at which the pipette will be used. Make 10 measurements of purified water, recording the weights. Volume settings are generally 10, 50 and 100% of nominal. Calculate the standard deviation. If results are 1/3 less than precision specifications (min. 3 con-secutive pipettes), continue to the next trial. Accuracy Trial: Take four weighings at each volume setting. Volume settings are generally 10, 50 and 100% of nominal. Calculate the mean volume.
Rules for use of the micropipettors: These are precision instruments which can easily be damaged. Treat them with respect and care. They are essential for your success in this course and shared amongst numerous students. Never measure higher or lower than the range of the pipettor allows. an exception to this rule is the P200 labeled 50-200 μl. Drop your pipette. Dropping your pipette might lead it to be out of calibration. So be very gentle and careful. Aspirate into the pipette. Believe us, it happens. If you're working with harsh chemicals, having it stuck inside your pipette might lead it to build up and give you inaccurate results.
For accurate measurements and to prevent damage to the micropipettes, follow these important guidelines: Set the volume only within the range of your micropipette. Have the proper size disposable tip in place on your micropipette before immersion into any solution. Always keep the micropipette in a vertical position when there is liquid in the tip. In a horizontal position, fluid can leak back into the piston. Use your thumb to control the speed at which the plunger rises after taking up or ejecting liquid. Letting the plunger snap back damages the piston and the volume dispensed may be inaccurate.
Scientists use carefully calibrated micropipettes to measure small volumes in the laboratory. Micropipettes draw liquid into a disposable plastic tip by creating a vacuum in the barrel above the tip. The liquid is dispensed when the vacuum is released. The plastic tip is changed between samples to prevent cross-contamination. Setting the volume of an adjustable volume micropipette: Choose the correct micropipette for the volume you are measuring. Make sure that the volume to be measured does not exceed the upper or lower volume setting of the micropipette. Determine the units measured by the micropipette by looking at the volume setting. The setting will appear in the window on the side of the micropipette. Note that the different micropipettes use different scales for their measurements. Some micropipettes are accurate to a tenth of a microliter, while others are accurate to one microliter. Set the volume by twisting the top of the plunger. In general, twisting the plunger clockwise reduces the volume, and twisting the plunger counter clockwise increases the volume.
Remember that the plunger has two stops. And that you push to the first stop when you were taking fluid up into the pipette tip to remove the last bit of fluid from the pipette tip push.
Instead, a disposable pipette tip is used to draw the liquid into and dispense from the micropipette. So in order to allow the safe, effortless and quick ejection of tips, micropipettes are provided with a tip ejection system. The tips can be easily removed from the micropipette by pressing the tip ejector button.
You may need to steady your hand by resting the micropipette against the back of your other hand. Slowly depress the plunger to the first stop* which will expel the DNA sample into the well. Do not release the plunger. Remove the tip from the gel well and then release the plunger.
When withdrawing liquids with the pipette, always release the plunger slowly. This prevents liquid from rushing into the end of the pipette and clogging it up. This is especially important with large volume pipettes (200-1000 µl).