Handling and measurement
Draw
Last updated
Pulling liquid from the vial into the syringe. In outline: wipe the stopper and let it dry, push the needle through, turn the vial upside down so the liquid covers the needle tip, pull the plunger back until the liquid reaches the mark you want, then clear any air and read it again. The mark is read at the flat front edge of the rubber plunger seal, the edge nearest the needle.
Why it matters here
Reading the barrel from an angle shifts where the mark appears against the plunger, so the same syringe gives different answers depending on where your eye is. Holding it upright at eye level removes that, and reading after clearing the air rather than before is what makes the number true.
What it is not
How much to draw is not a property of the syringe and is not something the equipment can answer. The barrel gives you a volume, the concentration of your vial converts that volume into an amount of material, and the amount itself comes from somewhere else entirely. A number of marks copied from someone else's vial does not transfer to yours, because their concentration is not yours.
Also called
- draw
- drawing
- draw up
- drawing up
- pull
- loading the syringe
- filling the syringe
Drawing up is the full phrase, and pulling or loading are the informal ones. In a graduated cylinder the reading point is the meniscus, the curve of the liquid surface, but a syringe gives you a flat rubber edge instead, so the reading point is that edge and not a curve.
Compounds carrying this term
None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.