Gilson guide to pipetting - Emidio Albertini

More documents

Recommendations

Info

sample What are air-displacement pipettes? Three things to remember 1 Recommended for aqueous samples and for general laboratory work 2 Always have a cushion of air (dead volume) between the pipette piston and the liquid sample 3 The piston is a permanent part of the pipette air cushion piston shaft disposable tip What are positive-displacement pipettes? disposable piston sample Three things to remember 1 Recommended for problem samples (viscous, dense, volatile, radioactive, corrosive) 2 Direct contact of the piston with the sample (no air cushion) 3 Disposable piston (not a permanent part of the pipette) shaft disposable capillary piston seal Chapter 1 9
10 How do air-displacement pipettes work? When the push-button is pressed on an air-displacement pipette, the piston inside the instrument moves down to let air out. Air is displaced by the piston. The volume of air displaced is equivalent to the volume of liquid aspirated. The schematic drawings (on the right) show how the piston determines the volume of air displaced and subsequently the volume of sample aspirated. How do positive-displacement pipettes work? Positive-displacement pipettes work like a syringe. There is no air cushion between the disposable piston and the sample. With no elastic air cushion to expand or contract, the aspiration force remains constant, unaffected by the physical properties of the sample. This allows the Microman operator to pipette very viscous or high density samples, such as mercury or toothpaste. 1 Set the volume The required volume is set. The piston moves to the appropriate position. 1 1 0 0 Set the volume The required volume is set. The piston moves down to the appropriate start position. 1 0 0
Page 1 and 2: Gilson guide to pipetting Second Ed
Page 3 and 4: Chapter 1 Selecting the best pipett
Page 5 and 6: Air- displacement pipette PIPETMAN
Page 7 and 8: 6 Selecting the best pipette for yo
Page 9: 8 1 .2 The working principle of air
Page 13 and 14: 12 Learning more All air-displaceme
Page 15 and 16: 14 Consider the volume of liquid yo
Page 17 and 18: 16 Selecting the right tip for your
Page 19 and 20: 18 2.2 Choosing the best tip for yo
Page 21 and 22: 20 Correct operation Chapter 3 To o
Page 23 and 24: 22 Fit a disposable pipette tip Pip
Page 25 and 26: 24 3 .3 Adjust the volume setting 1
Page 27 and 28: 26 Air-displacement / Forward mode
Page 29 and 30: 28 Air-displacement / Reverse mode
Page 31 and 32: 30 Positive-displacement In positiv
Page 33 and 34: 32 3 .5 Eject the used tip and stor
Page 35 and 36: 34 Preventing contamination Chapter
Page 37 and 38: 36 4.2 Decontaminating your Pipetma
Page 39 and 40: 38 Caring for your pipette Chapter
Page 41 and 42: 40 Step 2- Assess pipetting functio
Page 43 and 44: 42 Step 4- Disassembly n Disassembl
Page 45 and 46: 44 Control and calibration Chapter
Page 47 and 48: 46 6.2 How to calculate volumetric
Page 49 and 50: 48 Some remarks about balances With
Page 51 and 52: 50 GLOSSARY Accuracy* Air cushion a
Page 53 and 54: 52 APPENDIX APPENDIX I - Example of
Page 55 and 56: 54 APPENDIX APPENDIX III - Evaporat
Page 57 and 58: 56 NOTES

Gilson guide to pipetting - Emidio Albertini

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?