Glass Pipettes for Reagents?

From Carol Coker in Dallas:

Our manager wants to know the “gold standard” for hydrating coagulation reagents; do most people use glass class A pipettes? Also, do you use the same pipette for multiple reagents or for just one type?

Hi, Carol. I enjoyed meeting you last summer in Rochester. There would be nothing wrong with using glass pipettes to reconstitute coagulation reagents or plasma, since the glass is only touching the water or buffer and not the actual reagent or plasma. However, I can think of no reason to insist on glass volumetric pipettes as a reference method, since automated or semiautomated hand-held pipettes with plastic tips maintain their calibration very well and are less subject to technique-related random error. I don’t have access to the Clinical and Laboratory Standards Institute standards or guidelines for volumetric precision (the EP series), but given the need for pipetting bulbs and blowout or drainout techniques, glass just doesn’t seem practical.

As far as using the same pipette or pipette tip for multiple reagents, it is OK to do so as long as the tip has not touched the reagent vial.

We will probably generate some discussion on this topic, I look forward to our participants’ opinions.