L3: Pipetting Techniques (MANUAL-BASED)

Question 1

There are several types of pipettes but in the molecular biology laboratory the so- called what are used ?

Answer 1

Air-displacement micropipettors

Question 2

T or F

a given volume of air is expelled from the cylinder equivalent to the desired volume of liquid

Answer 2

T

Question 3

What is the volume capacity of micropipettes?

Answer 3

1ml to 0.1 ul

Question 4

Are attached to the pipettor which will hold the fluid to be transferred.

Answer 4

Disposable plastic tips

Question 5

The desired volume is set by ?

Answer 5

manipulating a piston to a proper position

Question 6

How is volume of air expelled?

Answer 6

when the piston is depressed through a plunger button

Question 7

T or F

In forward pipetting, second stop delivers the set volume of liquid being transferred

Answer 7

F (FIRST STOP delivers the set volume of liquid being transferred)

Question 8

T or F

The second stop is used to completely expel the liquid from the tip

Answer 8

T

Question 9

T or F

When sucking liquid into the pipettor, the second stop should be reached

Answer 9

F (When sucking liquid into the pipettor, the second stop sHOULD NOT be reached; get as far as the second stop only when EXPELLING last drop)

Question 10

T or F

In reverse pipetting, it is possible to have remaining fluid left in the tip after first stop

Answer 10

T

Question 11

Use this card to familiarize pipetting techniques

Answer 11

1. Adjust the volume adjustment dial to the correct volume.
2. Attach an appropriate tip to the pipettor shaft.
3. Press the plunger button to the first stop.
4. Submerge the tip into the solution and release the plunger button slowly and smoothly aspirate the liquid. Wait for one second to make sure that the desired volume of liquid has moved up into the tip.
5. To dispense the sample, place the tip end on the wall inside the transfer container at an angle of 10 to 40 degrees.
6. Push the plunger button carefully to the first stop, then wait one second and press the button to the second stop to deliver the remaining liquid.
7. Keeping the button pressed to the end, slowly remove the pipettor by sliding the tip up the wall of the vessel.
8. Release the plunger button.
9. Press the ejector button to eject the tip into a waste container.

Question 12

In aspirating, after submerging tip into solution and plunger is released slowly, how many second/s should you wait to make sure desired volume is moved up into tip?

Answer 12

One second

Question 13

To dispense the sample, place the tip end on the wall inside the transfer container at an angle of?

Answer 13

10-40 degrees

Question 14

When transferring, push the plunger button carefully to the first stop, then wait for how many second/s before pressing to second stop?

Answer 14

One second

Question 15

T or F

After transferring, you keep button pressed by swiftly removing the tip from the vessel

Answer 15

F ( you keep button pressed and SLIDE THE TIP UP the wall of the vessel)

Question 16

T or F

Make sure to hold the pipettor in tilted position

Answer 16

F (Make sure to hold the pipettor in a VERTICAL) position.

Question 17

T or F

Do not exceed the upper or lower limits of the pipettor.

Answer 17

T

Question 18

T or F

Change tips for each different solution

Answer 18

T

Question 19

T or F

Releasing the plunger button swiftly during withdrawal of sample prevents the entry of liquid into the pipettor shaft.

Answer 19

Releasing the plunger button SLOWLY AND SMOOTHLY during withdrawal of sample prevents the entry of liquid into the pipettor shaft.

Question 20

T or F

When using different liquid, it is ok to use the same tip

Answer 20

F (Change to a new tip for every different liquid)

Question 21

What do you do when there is air bubbles present in the tip?

Answer 21

1. Dispense liquid into original container
2. Aspirate slowly this time (observing proper immersion depth)