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World Precision Instruments

the pipette. However, a 0.1–0.2 PSI pressure imbalance will not cause a significant 
problem if the tip is small enough. The gravity of the fluid and the flow resistance 
caused by friction from the glass wall will both help to stop the solution flow at this 
pressure level. If the lowest pressure setting still can’t stop the fluid from oozing 
out, try to switch off the hold pressure to see if the gravity and friction are sufficient 
to counterbalance the backfill. In addition,  resetting  the regulator could allow the 
regulator to perform much better in this range (see the “Troubleshooting The Hold 
Pressure” on page 16).

The capillary action can also be reduced by adding a hydrophobic fluid (such as 
silicone oil) behind the hydrophilic saline solution. It can be completely eliminated 
by silanizing the shank of the pipette (silanization increases the 

θ

 in the LaPlace 

equation to 90º).

Micropipette Manufacture

The volume of fluid ejected is markedly dependent on the micropipette tip size. 
When using micron-sized tips a reduction in tip-size of a few percent may give an 
order of magnitude difference in the flow rate. With tip sizes less than 1µm, pressure 
ejection becomes increasingly difficult and special steps must be taken.

The most important of these steps is cleaning the glass. Small amounts of dust or 
grease can easily clog micron-sized tips. Cleaning with chromic acid solutions before 
pulling the electrode is commonly performed, but care must be taken to thoroughly 
rinse the pipettes to remove all traces of the chromic acid, which has some affinity 
for glass. Some researchers prefer hydrochloric or nitric acid.

Silanization of the glass is also recommended for small tips. With 1µm and smaller 
tips, capillary action becomes prohibitively large, and the hydrophilic surface of 
the glass greatly limits the flow of fluid through the tip. Silanization decreases the 
surface tension and allows the fluid to flow smoothly through the tip. For similar 
reasons, use of a capillary with an internal filament is contraindicated. Some of the 
many papers on the art of silanization are listed in the bibliography.

When using the vacuum line to hold and manipulate individual cells a large tip 
(about 10–20% of cell size) is recommended. To prevent damage to the cell this tip 
should be fire-polished. 

Volume Calibration

For ejected volumes greater than 1nL visual inspection using a microscope can 
be an accurate gauge of volume. A single pulse deposits a drop of fluid on the tip 
of the micropipette. The volume of this drop may be calculated by measuring the 
radius of the drop and assuming the drop to be spherical. Fig. 11 may be helpful 
in determining the volume for a given radius. See “Appendix” on page 19 for a 
comparison of spherical and cubical volumes.

Содержание PicoPump PV830

Страница 1: ...PV830 Pneumatic PicoPump World Precision Instruments INSTRUCTION MANUAL Serial No _____________________ 042712 www wpiinc com...

Страница 2: ......

Страница 3: ...cking 2 INSTRUMENT DESCRIPTION 3 Setup 5 Vacuum Input 6 Pressure Input 6 Eject Pressure Port front panel 6 Vacuum Port 8 OPERATING INSTRUCTIONS 9 Front Panel 9 Rear Panel 10 Techniques In Microinjecti...

Страница 4: ...iv World Precision Instruments...

Страница 5: ...ally useful alternative to electroionophoresis since it does not mandate the use of charged ions Two different positive pressures may be applied one for ejection at high pressure and a second lower pr...

Страница 6: ...any parts are missing at 941 371 1003 or customerservice wpiinc com Returns Do not return any goods to WPI without obtaining prior approval RMA required and instructions from WPI s Returns Department...

Страница 7: ...position of the Vac Hold toggle switch This feature allows the pressure ejection channel to have a mild sucking action when pressure is not being applied A manual pneumatic switch also allows the vacu...

Страница 8: ...or Depress the plastic collar to remove tubing Fig 5 The PicoPump Pressure and Vacuum ports are located on the rear panel of the PV830 To install the hard tubing push it into the port until the tubing...

Страница 9: ...asily while metal tubing may require more effort For a diagram of the setup see Fig 6 Air or Nitrogen Supply 150 psi max Vacuum Pump or Line Pressure Input Vacuum Input Hold Eject Port Micropipette Ho...

Страница 10: ...o a nitrogen regulator on a N2 tank Recommended gases are dry air nitrogen or argon Never use corrosive gases If an air pressure line containing oil or water vapor is used an external filter is recomm...

Страница 11: ...hen using a MPH6S handle a firmer hold on the glass can be achieved by using two gaskets in the micropipette holder NOTE Capillary holders can be obtained from WPI which contain Ag AgCl half cells The...

Страница 12: ...ak when attaching or removing the tubing Before inserting the pipette place a gasket of the correct size in the cap Gasket Color Green Black Red White Pipette Diameter mm 1 0 1 2 1 5 1 65 WARNING DANG...

Страница 13: ...n dial yielding good pressure resolution The pressure regulating mechanism functions by continuously bleeding a small amount of gas This bleed rate increases as the difference between the input pressu...

Страница 14: ...electronic timer controls the time duration that the pressure solenoid stays open and the three commands serve only to start the timer Long pulses in the timed mode may be aborted by pressing the Stop...

Страница 15: ...helps you to correctly use the Hold pressure The backfilling flow rate is determined by the pressure of capillary action and the tip size Since the tip size is often determined by the requirement of t...

Страница 16: ...s cleaning the glass Small amounts of dust or grease can easily clog micron sized tips Cleaning with chromic acid solutions before pulling the electrode is commonly performed but care must be taken to...

Страница 17: ...ation The same technique may be used though if the drop is kept submerged under oil Droplets may seem to disappear after emergence from the tip Sometimes this is due to creepage of the aqueous fluid b...

Страница 18: ...approximately 1mV for every 10 PSI of applied pressure Multibarrel Microinjection For injection with multibarrel micropipette the PolyFil multibarrel micropipette coupling kit can be purchased from W...

Страница 19: ...e 1 Kit MPH6S for 1 5 mm pipette 5 ft tubing assembly 5430 20 PicoNozzle 1 Kit MPH6S for 2 0 mm pipette 5 ft tubing assembly 5430 ALL PicoNozzle 2 Kit MPH6S Micropipette Holder specify 1 0 1 2 1 5 or...

Страница 20: ...port will push the diaphragm and return the O ring to the seat To introduce a high pressure 1 Remove the 1 4 hard pressure tubing from the back of the pump 2 Use pieces of tubing with 1 4 OD to make a...

Страница 21: ...ng the knobs Over tightening the knobs will damage the regulators Vacuum Vacuum Input rear 0 30 0 in Hg 101kPa Vacuum Output 0 29 9 in Hg 101kPa Lowest Regulated Vacuum 3 in water 0 7kPa Regulator Acc...

Страница 22: ...hysical Specifications Power 95 130 VAC or 190 260 VAC switch selectable single phase 50 60 Hz 20VA Temperature 10 C 50 F to 40 C 104 F Dimensions 3 5 x 17 x 9 5 in 89 x 432 x 242 mm Mountable in stan...

Страница 23: ...L 215 m 267 m 1nL 100 m 1 24 m 100pL 46 m 57 m 10pL 21 5 m 27 m 1pL 10 m 12 4 m Fig 13 This graph compares the dimensions of a cube and a sphere with the same internal volume Volume of a Micropipette...

Страница 24: ...ion sensitive microelectrodes J Neuroscience Methods 8 231 247 1983 Deyhimi F and J A Coles Rapid silylation of a glass surface Choice of reagent and effect of experimental parameters on hydrophobici...

Страница 25: ...PV830 Pneumatic PicoPump World Precision Instruments 21...

Страница 26: ...22 World Precision Instruments DECLARATION OF CONFORMITY...

Страница 27: ...indirect special or consequential arising from a failure of this product to operate in the manner desired by the user WPI shall not be liable for any damage to data or property that may be caused dir...

Страница 28: ...44 0 1462 424700 Fax 44 0 1462 424701 E mail wpiuk wpi europe com Germany Zossener Str 55 10961 Berlin Tel 030 6188845 Fax 030 6188670 E mail wpide wpi europe com China Hong Kong WPI Shanghai Trading...

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