Serological vs Volumetric Pipette: Which to Use and When
Pick by the job, not by habit
Burette vs pipette, side by side
The calibration difference that determines accuracy
A volumetric pipette has one calibration mark — one volume, one accuracy point. At that mark, it meets the tightest tolerance in glass pipette design (ISO 648 Class A: ±0.03–0.06 mL). It is TD (To Deliver): drain fully, leave the residual in the tip, do not blow out.
A serological pipette has graduation marks from zero to full capacity. It is TC (To Contain): it must be blown out completely to deliver the stated volume, because the calibration assumes the tip residual is expelled. Blowing out a volumetric pipette over-delivers; not blowing out a serological under-delivers.
Sterility and cell culture work
Serological pipettes are the standard for sterile liquid handling in cell culture. They come individually wrapped, plugged, and gamma-irradiated. Volumetric glass pipettes require autoclaving and are not standard in aseptic cell biology work. For media additions, reagent transfers, and any sterile bench work, serological pipettes are the practical choice regardless of the tolerance comparison.
When the tolerance difference actually matters
For most cell culture and reagent-addition work, the tolerance difference between serological and volumetric is irrelevant — adding 10 mL of media to a flask does not require ±0.03 mL accuracy. The tolerance difference matters in analytical chemistry: preparing standard solutions, titration setups, and reference-method work where the volume directly feeds a calculation. Use volumetric for those; serological for everything else at the same volume range.
