# Pipetting Technique

### From BODDoctor

A simple procedure can ensure correct pipetting technique when making dilutions. The following procedure can be used to check technique, or the pipette itself.

## [edit] Pipette Testing Procedure

- Obtain a 300 mL beaker of DI water
- Tare a second 300 mL beaker on a quality analytical balance (that can handle its weight).
- Pipette a quantity of water from the 300 mL beaker full of water to the empty (or mostly empty one) on the balance.
- The density of water is approximately 1 g/mL so the number of grams registered on the balance should be about the same as the mL of water measured with the pipette. The following formula will calculate the density of water as g/mL for a given temperature in C.

density (g/mL) = 1.53647145·10^{-8}T^{3} - 5.857243231·10^{-6} T^{2} + 1.65948294·10^{-5} T + 1.00003975