Volumetric Pipettes Volumetric pipettes labeled TD (to deliver) at the upper end are designed to deliver the volume stated on the pipette. There will always be a small amount of liquid inside the tip after pipetting. If this liquid is blown out you will have delivered slightly more than the designed capacity of the pipette. Almost all of our pipettes are TD pipettes. However, other types do exist: Pipettes labeled TC (to contain) are designed to contain the volume stated on the pipette. Therefore, all liquid on a TC pipette should be expelled to obtain the desired volume.