It is a common experience that low quality tip can destroy the performance of even the best quality pipette. The tips impact will be reflected in your precision results. In order to illustrate tips' impact on precision, Capp has made a small test, where we pipetted a colored liquid into a standard tip and ExpellPlus low retention tip. The amount of liquid still remaining in the tip after expelling can be seen on the picture below.
We came to the conclusion that ExpellPlus low retention tips deliver within 0. This is possible thanks to the unique technology of extra polished tip interior, minimizing the liquid retention and improving your results up to 7 times more than with standard tips. Thirdly, the user themselves can do much in order to improve their pipetting technique.
Inspired by ISO , we have summed up a few tips on how to pipette, eliminating sources of error in pipetting: 1. Use a proper pipette tip low retention and make sure it fits the pipette. Work at room temperature, allowing liquid and equipment to equilibrate. Examine the tip before sample dispensing and wipe it only if there is liquid on the outside of the tip, being careful to avoid touching tip's orifice.
Pre-wet the pipette tip: Aspirate and expel the sample liquid at least 3 times before aspirating a sample for delivery. Through a combination of curiosity and discipline, creativity and precision, he works with his fellow Artelians to build outside-the-box solutions that are efficient, easy-to-use, highly effective and based on science.
Their goal: to ensure that each customer finds new opportunities and executes new solutions to achieve productivity and compliance objectives. When not at Artel, Kirby takes up his own instruments, the saxophone and piano, playing for the approval of Charlie Parker and Gabriel Faure.
Master your instrument, master the music. An important part of building high-quality products, and providing services that rely on those products, is ensuring that the components and supplies are also high-quality and readily available.
Which is why Jack focuses on keeping supply-side relationships top notch. When not at Artel, Jack is an avid traveller, gardener, and connoisseur of cinema and literature. You know the cost of replacing it, but not the cost of a dissatisfied customer. Edwards Deming. In practice, this means listening to customers and leveraging his broadly eclectic scientific and business background to identify technological solutions that improve data quality and productivity.
The many years at the bench have given Graham a deep appreciation of the importance of reducing sources of noise and variability which, together with experimental controls, can help save weeks and even months of wasted time. These activities give George a deep understanding of regulatory compliance which, coupled with his metrology and quality expertise, he uses to help customers improve data quality and efficiency while maintaining regulatory compliance. This help is especially critical for customers making process improvements, as change can be challenging in regulated environments.
With no stated reference temperature, the NFL cannot possibly regulate ball pressure to plus or minus 0. Edwards Deming, but more likely from Paul Batalden. When not at Artel, Doreen likes to spend time with her family some of whom she also sees at Artel , gardening, and travelling with her many sisters and brother. Table 1. Lab Report 2: Impact of Pipetting Technique. Eliminating sources of error 1. Not too hot… not too cold… Variation in the temperature of the solution being pipetted was observed to be the second largest cause of pipetting error in this study.
Figure 1. Wendy Vaccaro Director Technical Services. An Artelian since Standards Developer since Keeping a continual focus on optimizing laboratory productivity, particularly in an increasingly global environment, Bjoern has been contributing to the development of international standards for over 10 years.
Contact Bjoern. Heidi Redlon Regulatory Affairs Specialist. Contact Heidi. An Artelian since Standards Developer since Richard has been applying his scientific expertise to the development of international standards for over 25 years. Contact Richard. Contact George.
An Artelian since Creating products at the intersection of corporate strategy, market need, and available technology Richard combines his scientific education, love of learning, curiosity, and passion for making things work better to build products that help life science labs meet quality and productivity goals. Kirby Pilcher President and Co-founder.
In addition to the features of the pipette, laboratory practice and user experience are the main factors affecting precision. The DIN standard does not give individual limits for accuracy and precision, but uses a combined error limit: the F-value. Table 2 shows the error limit according to the DIN standard for single-channel air displacement pipettes.
For multichannel pipettes, these limits are doubled. With variable volume pipettes, the nominal volume is the maximum volume. The absolute vl limit of the nominal volume applies to every selected volume throughout the volume range. For example, for a 20 - vl pipette, the error limit is 2.
Table: DIN error limits for single channel air displacement pipettes. Error-free pipetting requires both precision and accuracy. A number of factors can effect these specifications, which are the main quantitative parameters for evaluating pipette performance.
Accurate, but not precise: The mean volume is the correct set volume, but separate pipettings differ from the set volume. Precise, but not accurate: There is no variation between the separate pipettings, but the mean volume differs from the set volume.
Accurate and precise: The mean volume is the set volume and there is no variation between different pipettings. Note: Autoclaving has a limited spectrum of action and will not destroy RNA for example. It is also important to note that certain parts of a pipette - for instance the piston and the handle cannot be autoclaved without altering accuracy and precision.
Question: What is the difference between air displacement and positive displacement pipettes? Answer: Both types of pipettes have a piston that moves in a cylinder, or capillary.
In air displacement pipettes, a specified volume of air remains between the piston and the liquid. This keeps air from entering the tip, preventing contamination effectively. Air displacement pipettes are meant for general use with aqueous solutions. Positive displacement pipettes are used for high viscosity and volatile liquids.
Answer: You can do so using an air displacement pipette with standard or wide orifice tip reverse pipetting, slowly. An alternative to this is to use a positive displacement system. Question: How can I prevent liquid dropping out of the tip when pipetting volatile compounds?
Answer: If you use air displacement pipettes, aspirate and dispense the liquid a few times keeping the tip in the liquid. By doing so, the air inside the pipette will be saturated with vapor of the volatile compound. It is recommend using positive displacement pipettes for highly volatile compounds, since the built-in piston tip is in direct contact with the liquid. Answer: The pipettes are calibrated by weighing distilled or de-ionized water of 20 - 25C. With warm liquids, you will get a smaller mass with a certain volume, with cold liquids, you will get a higher mass.
Are you sure? Twitter Facebook Gplus Youtube. Remember me. Pipette Stands. Pipette Parts. Reagent Reservoirs. Tip Compatibility Chart. Universal Tips Brochure. Specialty Tips Brochure. Order Tip Samples. ISO Certified Laboratory. Guide to Pipetting Understanding Pipettes Pipette terms: Adjustment - altering the pipette so that the dispensed volume is within the specifications. Aspirate - to draw up the sample.
Blow-out - to empty the tip completely. Dispense - to deliver the sample. Air Displacement Pipettes Air Displacement Pipette, used for standard pipetting applications, is highly accurate.
How does an Air Displacement Pipette work? The piston moves to the appropriate position when the volume is set. When the operating button is pressed to the first stop, the piston expels the same volume of air as indicated on the volume setting.
After immersing the tip into the liquid, the operating button is released. This creates a partial vacuum and the specified volume of liquid is aspirated into the tip. When the operating button is pressed to the first stop again, the air dispenses the liquid.
To empty the tip completely the operating button is pressed to the second stop blow out. Factors affecting the accuracy of Air Displacement Pipettes: Temperature The most important factor in pipetting accuracy is the liquid temperature. How does a positive displacement pipette work? When the operating button is pressed to the stop, the piston descends to the tip opening. After the tip is immersed into the liquid, the operating button is released.
The plunger is then raised and a partial vacuum is created. This causes the liquid to enter the tip. When the operating button is pressed again, the piston descends, expelling the liquid from the tip.
General guidelines and Pipetting techniques General guidelines Check your pipette at the beginning of your working day for dust and dirt on the outside. Set the volume within the range specified for the pipette.
Hold the pipette so the "grippy finger rest" rests on your index finger. To maximize accuracy, the pipette, tip and liquid should be at the same temperature. Avoid contamination to or from fingers by using the tip ejector and gloves. Forward Pipetting technique Press the operating button to the first stop.
Dip the tip into the solution to a depth of 1 cm, and slowly release the operating button. Wait seconds and withdraw the tip from the liquid, touching it against the edge of the reservoir to remove excess liquid. Dispense the liquid into the receiving vessel by gently pressing the operating button to the first stop and then press the operating button to the second stop.
This action will empty the tip. Remove the tip from the vessel, sliding it up the wall of the vessel. Release the operating button to the ready position. Reverse Pipetting technique The reverse technique is used for pipetting solutions with a high viscosity or a tendency to foam.
Reverse pipetting is only possible with air displacement pipettes Press the operating button to the second stop. This action will fill the tip with a volume that is larger than the set volume. Dispense the liquid into the receiving vessel by pressing the operating button gently and steadily to the first stop. This volume is equal to the set volume. Hold the button in this position. Some liquid will remain in the tip, and this should not be dispensed. The liquid remaining in the tip can be pipetted back into the original solution or disposed together with the tip.
Repetitive Pipetting technique This technique is intended for repeated pipetting of the same volume. Press the operating button to the second stop. Withdraw the tip from the liquid, touching it against the edge of the reservoir to remove excess liquid.
Dispense the liquid into the receiving vessel by gently pressing the operating button to the first stop. Continue pipetting by repeating steps 2 and 3. Pipetting whole blood Use forward technique steps 1 and 2 to fill the tip with blood do not pre-rinse the tip. Dip the tip into the blood and press the operating button to the first stop. Make sure the tip is sufficiently below the surface.
Release the operating button slowly to the ready position. This action will fill the tip with blood. Do not remove the tip from the solution. Press the operating button to the first stop and release slowly. Repeat this process until the interior wall of the tip is clear. Press the operating button to the second stop and completely empty the tip. Remove the tip by sliding it along the wall of the vessel. Displacement Standard wide orifice Pos.
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