Micropipettes Why they are useful How they work How to care for them

Micropipettes are essential equipment in a modern biology lab • • • • • For moving liquids from container to container Can measure tiny volumes, very precisely Come in a variety of sizes All require special disposable tips They are fragile and

expensive

Micropipettes have different volumes Volumes adjustable with dial • • • P20: 20 microliters (=20 uL) max vol.

P200: 200 uL max.

P1000: ____uL max vol = ______

Micropipettes have different volumes Volumes adjustable with dial • • • P20: 20 microliters (=20 uL) max vol.

P200: 200 uL max.

P1000: __20uL max vol = _1mL__

Parts of a mircopipette 1. Volume adjustment 2. Tip ejector button 3. Plunger 4. Adjustment threads 5. Volume indicator window 6. Tip ejector bracket 7. Shaft 8. Disposable tip

Pipette tips • • Different tips for different kinds of pipettes Micropipettes are never used without an appropriate tip

Pipettes have two springs “First stop”: calibrated volume “Second stop”: maximum volume of pipette How micropipettors work

What is the volume indicated?

What is the volume indicated?

6.84 uL 132.5 uL 264 uL=____mL

How to use the pipette A: Press plunger down to FIRST STOP BEFORE putting in liquid (make sure you adjusted to the right volume!) B: Release plunger slowly, taking up correct volume C: Put tip into new tube and press plunger to SECOND STOP, expelling liquid D: Remove tip from liquid BEFORE releasing plunger E: Release plunger and eject tip

How to take care of the pipettes • • • Never use a pipette without a tip Never adjust a pipettor beyond its maximum (or minimum) volume range Never place a pipet on its side with liquid in the tip

What is wrong with this picture?

Pressing the tip ejector button • Note: tip ejector doesn’t always work with certain tips