Biology Lab: Measurements and Measuring

Microliter (μl):

one millionth of a liter (10-6 L) and one thousandth of a milliliter (10-3 mL).

Serological pipette

graduated all the way to the tip

10 ml serological pipette

has a line at the top marked 0. When the pipette is filled to this line, it contains 10 ml.

The ten smaller graduations underneath the line represent 0.1 ml.

Plunger

dispenses the set volume.

Volume adjustment knob

enables the user to change the amount of liquid being dispensed as shown by the volume indicator.

Body of the pipette

where you hold the instrument

Shaft

the piece of the instrument in which a disposable tip is placed.

Polypropylene tips

often sterile and is the only part of the pipette that contains the liquid.

First stop

used to measure and take up the correct volume.

Seconf stop

used to completely expel the liquid you are measuring.

Dilute

to make a solute less concentrated by the addition of a solvent.

Dilution =

(Vol A) / (Vol A + Vol B)

Dilution Factor=

C2/C1 = V2/V1