1

REGIONAL BIOTECH AT THE UNIVERSITY OF TEXAS-PAN

AMERICAN

BIOSCIENCE EDUCATION FOR THE RIO GRANDE

VALLEY

2

AN INTRODUCTION TO USING A DIGITAL MICROLITER PIPETTE

PIPETMAN & EAGLE BRANDS

3

FUNCTION OF THE MICROLITER PIPETTE

In the biotechnology laboratory, scientists use an instrument called a microliter pipette or micropipette to measure and transfer precise amounts of liquid reagents

The micropipette is a precision instrument calibrated in microliters (L).

1ml = 1000 (L)

4

CAREFUL HANDLING OF THE MICROPIPETTE

The micropipette must be handled with great care, to avoid damage.

A damaged micropipette may produce imprecise measurements and this could affect the results from an experiment.

Do not rough-handle or drop the micropipette

5

CAREFUL HANDLING OF THE MICROPIPETTE

Do not adjust the micropipette volume above or below that recommended. If you encounter resistance while turning the volume adjustment wheel, stop and inform your instructor immediately.

When not using the micropipette, lay it flat on the workbench or hang it on the pipette stand in front of you.

6

PARTS OF A MICROPIPETTE (EAGLE BRAND)

7

PARTS OF A MICROPIPETTE (PIPETMAN BRAND)

8

SETTING THE VOLUME ON THE P20 & E20

In the digital volume indicator window are three vertical numbers read from top to bottom

The top number indicates “tens” microliters (L)

The middle number indicates “units” microliters (L)

The bottom number indicates “tenths” microliters (L)

9

SETTING THE VOLUME ON THE P200 & E100

In the digital volume indicator window are three vertical numbers read from top to bottom

The top number indicates “hundreds” microliters (L)

The middle number indicates “tens” microliters (L)

The bottom number indicates “units” microliters (L)

10

SETTING THE VOLUME ON THE P1000 & E1000

In the digital volume indicator window are three vertical numbers read from top to bottom

The top number indicates “thousands” microliters (L)

The middle number indicates “hundreds” microliters (L)

The bottom number indicates “tens” microliters (L)

11

SETTING THE VOLUME ON THE MICROPIPETTE

Hold the micropipette in one hand and with the other hand, turn the volume adjustment knob until the volume indicator displays the desired volume. See tables and pictures in the next slide for examples

IF THE VOLUME ADJUSTMENT KNOB IS HARD TO TURN, STOP AND CALL THE INSTRUCTOR. DO NOT TRY TO FORCE THE KNOB TO TURN BECAUSE YOU WILL DAMAGE THE MICROPIPETTE

12

 

  P20 E20

TENS 1 1

UNITS 8 8

TENTHS 3 3

THIS EXAMPLE IS A SETTING FOR 18.3 MICROLITERS (L)

  P200 E100

HUNDREDS 1 1

TENS 0 0

UNITS 0 0

THIS EXAMPLE IS A SETTING FOR 100 MICROLITERS (L)

  P1000 E1000

THOUSANDS 0 0

HUNDREDS 8 8

TENS 7 7

THIS EXAMPLE IS A SETTING FOR 870 MICROLITERS (L)

13

MEASURING AND TRANSFERRING LIQUID REAGENTS

Turn the volume adjustment knob to the desired volume

Hold the micropipette so that the tip ejector button is facing the user and the thumb is free to depress the push button

14

MEASURING AND TRANSFERRING LIQUID REAGENTS

Select and open a box containing the correct size tips to be used.

Place the pointed end of the micropipette shaft into one of the tips and press down firmly, then lift-up the micropipette with tip attached.

YOU MUST NEVER USE THE MICROPIPETTE WITHOUT A TIP ATTACHED !!!

15

MEASURING AND TRANSFERRING LIQUID REAGENTS

Using your thumb, depress the pushbutton to the first stop.

Immerse the micropipette tip about half-way into the reagent you are measuring.

Make sure the reagent does not touch the micropipette shaft

16

MEASURING AND TRANSFERRING LIQUID REAGENTS

With the pipette tip immersed in the reagent, draw the reagent into the tip by slowly raising your thumb and releasing the pushbutton

Remove the tip from the reagent by lifting the micropipette

Visually examine the tip to make sure it contains reagent and that there are no bubbles present.

17

MEASURING AND TRANSFERRING LIQUID REAGENTS

Move the micropipette towards the transfer container which is to receive the measured reagent

Expel the reagent inside the tip into the transfer container by placing the tip in the transfer container and slowly depressing the pushbutton with your thumb as far as it will go.

With your thumb still holding down the depressed push button, lift the micropipette and tip out of the transfer container

18

MEASURING AND TRANSFERRING LIQUID REAGENTS

With the micropipette and tip out of the transfer container, slowly raise your thumb, releasing the pushbutton.

Position the micropipette on top of the waste container

Dispose of the tip by using your thumb to press down on the tip ejector