Why condition a pipet

Never shoot or squirt the liquid into the air; doing so can affect your measurement results. Use the blow-out at the same time. Water tension can sometimes prevent all of the liquid from exiting the tip so be sure to pull the residual amount out of the tip. There are environmental factors that can affect the state of a pipette, including temperature, altitude, and liquid density, so be cognizant of these factors when pipetting. Reilly is showing at the right.

When the bottom of the meniscus coincides with the calibration mark, your pipet contains a precisely measured volume, as in the image at the left. The pipet can then be removed from your reagent solution, transferred to the receiving flask and allowed to drain.

A volumetric pipet should not be "blown out" to eject all liquid at the tip because volumetric pipets are calibrated in a manner that takes into account the solution which remains at the tip due to surface tension. The "high-tech"pipet bulb is an Eppendorf bulb. It can be placed firmly on the mouth of the pipet. At the side of the Eppendorf is a protruding lever attached to a slide. Pull it down to create a vacuum inside the bulb.

Use your thumb to push the two way valve up when you are ready to draw your solution into the pipet, as shown at the left, but make sure the nozzle of your pipet remains below the surface of the solution right so that you don't suck air into your pipet causing lots of solution to pass into the filter in the bulb area which will require disassembly, drying out and replacement of parts.

When a sufficient amount of the solution has been drawn in so that the meniscus is above the calibration mark, use your thumb to slide the two-way valve down, as shown at the left.

Do it gently so that the meniscus drops slowly to the calibration mark. Then you can transfer the solution in the pipet to the receiving flask and push the two-way valve lever down to empty the pipet. The nozzle of the pipet can be kept in the open air for the transfer, as shown at the right.

Finally, pipettes and burettes accumulate inert solid material which must be removed from time to time. Here at the left is the nozzle of a burette which has material which will not pass through. You may have to use a wire, available on the lower ledge of the burette case, to clean out this material. It is best to do it with the petcock valve removed so that when you do a reverse wash after poking it free, the material can be washed out at the point of the valve instead of at the other end of the burette cylinder.

If you share equipment with someone else, such as a lab partner, and she didn't clean the burette as thoroughly as you would, it's possible you could introduce some contaminants into your titrant if you don't rinse the burette first.

Depending on the nature of these contaminants, they might have an effect on the concentration of your titrant and the reaction that takes place in your sample. The second and more important reason for rinsing your burette has to do with water.

When you're cleaning your glassware, you use water to rinse it off. If the burette is not completely dry by the time you use it, the remaining traces of water on the inside will make your titrant more dilute and thereby change its concentration. Consequently, if you don't rinse your burette with titrant and there really is some water remaining inside, the titrant you dispense will be more dilute than it should be.

If there's one place where haste makes waste, it's in the lab. Performing preventive maintenance routinely will help to minimize malfunctions and keep your instruments in good operating condition. Depending on the criticality of the pipette, the types of solutions being transferred with the pipette, and the age of the pipette, maintenance schedules can vary. Note: Adjustment of the pipette should be performed only when maintenance does not resolve the issue. Through hiring, training and guiding her team, she nurtures productive, long-lasting customer relationships.

When not assisting customers, Wendy likes to stay active by biking, boating, and taking long walks in beautiful Maine. 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.

Heidi contributes almost 40 years of Regulatory Affairs and Quality Assurance experience to the Standards Leadership team.

Having worked for decades in FDA-registered companies, she is well-versed in FDA regulations, audits, and inspections. Richard has been applying his scientific expertise to the development of international standards for over 25 years.

In , he became involved in the revision of DIN series of standards related to pipettes and other piston-operated apparatus, which led to the development of the ISO series of standards.

He authored numerous papers and presentations on the topic of pipette calibration, which are referenced in compliance standards, such as the checklists issued by CAP College of American Pathologists. George is also a technical expert in the revision of all parts of the ISO series of standards and proposed the development of the new ISO standard on Operator Training and Pipetting Technique. Serving as chair of the US technical advisory group to the ISO technical committee responsible for laboratory equipment, George is responsible for achieving consensus among US experts and articulating this US consensus positions the ISO international technical committee.

George chairs the ASTM sub-committee on laboratory apparatus and serves as secretary to the parent main committee. Responsible for financial planning and analysis, evaluating strategic opportunities, budgeting, benefits, and compensation, Kathleen uses her long history of doing mergers and acquisitions from a consulting and business side to bring analytical excellence to strategic evaluations, and her experiences at larger companies to advance established processes.

When not at Artel, Kathleen uses all her experience in efficiency and productivity to care for her two daughters and their cat, dog, and horse and, in the very little time left over after that, enjoys travelling to other countries, meeting new people and learning about other cultures.