BellworkBellwork What is an SOP?What is its purpose?Why is Quality Control important?

04/18/23 Property of CTE Joint Venture 1

How to Properly Use a Micropipettor

Bioscience: Quality Control

04/18/23 2

ObjectivesObjectivesIdentify the different sizes of

micropipettors.Recognize when to use which

size micropipettor.Demonstrate ability to

accurately set and use the different sized micropipettors.

Demonstrate ability to successfully complete Micropipetting SOP.

04/18/23 Property of CTE Joint Venture 3

PurposePurposeIntroduce the laboratory instrument: micropipettor.

Practice using different sized micropipettors to gain accuracy and precision.

Introduce the process of correctly following an SOP.

04/18/23 Property of CTE Joint Venture 4

What are Micropipettors?!What are Micropipettors?!We will be using 3 different

sizes of micropipettors:◦ P20◦ P200◦ P1000

Very expensive and very fragile – USE Responsibly!!!

Used to measure liquid amounts LESS THAN or EQUAL to 1 mL.

04/18/23 Property of CTE Joint Venture 5

When to Use Each When to Use Each Micropipettor Micropipettor Each micropipettor has its name

on the top cap.Each micropipette has a limit:

◦P20: 0.5 to 20.0 uL◦P200: 20 to 200 uL◦P1000: 200 to 1000 uL

04/18/23 Property of CTE Joint Venture 6

Write onWrite onyour Slates: your Slates:

Which micropipettor will you use for the following

volumes?254 uL

7 uL98 uL

645 uL145 uLPROPERTY OF PIMA COUNTY JTED, 2010 2

How to Set/Adjust the How to Set/Adjust the MicropipettorMicropipettorAdjustment knobs are on the

side of each micropipettor.

Red digits indicate a decimal place

04/18/23 Property of CTE Joint Venture 8

How to Load and Dispense How to Load and Dispense LiquidsLiquidsPlace clean plastic tip at end of

micropipettorPlunger has TWO different ‘stop’

positions.◦First is used to load (pick up) liquid◦The second (lower) is used to dispense

(expel) liquidTwo stop method is what creates

accuracy and precision of instrument – YOU MUST BE CONSISTENT

04/18/23 Property of CTE Joint Venture 9

Micropipettor Use – Video Micropipettor Use – Video QuestionsQuestionsWhile watching video answer the

following 3 questions:◦How does the scientist know that she

has the correct micropipettor?◦Why do you use the first stop on the

plunger?◦How do you dispense liquid?

04/18/23 Property of CTE Joint Venture 10

Micropipettor Use – Demo Micropipettor Use – Demo VideoVideo

Property of CTE Joint Venture 11

http://www.youtube.com/watch?v=nv5Bi2Wy1KU&feature=relatedCommon errors

http://www.youtube.com/watch?v=wlO4zJLR8R8&feature=related04/18/23

How to pipet

Micropipettor Use - DOsMicropipettor Use - DOsAlways use the correct

micropipettor for the volume being measured

Always use the correct pipette tip for each size micropipettor

Use the first stop for loadingUse the second stop for

dispensingRelease plunger slowly

04/18/23 Property of CTE Joint Venture 12

Micropipettor Use - Micropipettor Use - DON’TsDON’Tshttp://www.youtube.com/watch?

v=1J3w4cS2MvMNO Double Dipping

◦When in doubt – CHANGE TIPS!!Don’t place tip into liquid too deeply.Use the two stops appropriatelyDon’t squirt liquid out too quicklyDon’t point tip up – this will

contaminate the barrel

04/18/23 Property of CTE Joint Venture 13

Partner PracticePartner Practice

Work with a partner to Work with a partner to create a list of 5 things create a list of 5 things

you should check you should check before using your before using your micropipettors.micropipettors.

Use your slates to make a list. Be ready to be called on.

04/18/23 Property of CTE Joint Venture 14

Micropipettor LabMicropipettor LabYou will be working in pairs:

◦Who will be leader/implementer?set-up/clean-up?

Both people in your group need to complete the pipetting portion of this lab.

Write down materials and procedures into your laboratory notes.

04/18/23 15

Micropipettor Lab: Micropipettor Lab: MaterialsMaterialsFor each pair you need:

◦Two micropipettors (P20, P200)◦One box of yellow tips◦Two microtiter plates◦One set of dyes (red, yellow, blue)◦One 50 mL beaker of water◦Two plastic sheet protectors

04/18/23 16

Micropipettor Lab: ResultsMicropipettor Lab: ResultsYou will use a variable

micropipette to prepare seven different dye mixtures in the wells of a microtiter plate.

You will then dispense 5 μl of each of the seven diluted dye solutions onto a pipet card in triplicate.

04/18/23 Property of CTE Joint Venture 17

Micropipettor ProceduresMicropipettor ProceduresGather materialsLabel a microtiter plate with your

initials and label seven of the wells as number 1 – 7.

MAKE SURE TO CHANGE TIPS INBETWEEN EACH DISPENSE.

04/18/23 Property of CTE Joint Venture 18

Micropipettor Lab: Micropipettor Lab: Procedures (cont.)Procedures (cont.)

04/18/23 Property of CTE Joint Venture 19

Prepare the dye solutions, one per well, using the ingredients shown in the following table.

You will fill in LAST THREE columns.Well Red (uL)

Blue (uL)

Yellow (uL)

Water (uL)

Total (uL)

Resulting Color

Under, over, correct?

1 5 - - 40

2 - - 10 35

3 - 10 10 25

4 5 15 - 25

5 13 - - 32

6 - 10 - 30

7 6 - 6 33

Micropipettor Lab: Micropipettor Lab: VerificationVerificationOnce solutions are made, set

your micropipettor to the Total Volume you determined and check the volume in the well in each well.◦If you under pipetted, you will see air

at the end of the tip.◦If you over pipetted you will have

liquid left in the tube.Record results on chart.

04/18/23 Property of CTE Joint Venture 20

Micropipettor Lab: Micropipettor Lab: Consistency/PrecisionConsistency/Precision

Once you have checked your pipetting accuracy using the micropipette, practice dispensing liquids by placing 5 uL of each dye onto a plastic sheet protector in triplicate.

You will have 7 rows of three drops neatly arranged on your sheet protector when complete.

Have your teacher sign-off your lab results and then complete closure.

04/18/23 Property of CTE Joint Venture 21

I now

understand . . .I would like to

know

more about . . .

I could

teach

someone

else to . . .

I need more help

with . . .

PROPERTY OF PIMA COUNTY JTED, 2010 22