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Microinjection

Posted: Thursday, May 2, 2013

Microinjection

Microinjection uses either a metal needle or a glass micropipette to inject small liquid volumes. For example, genetic material may be inserted into a living cell, a drug introduced into an eye or brain, or fluid injected into a muscle. Typically, microinjection is performed under a microscope. A stereotaxic setup may be required.

WPI offers a variety of pumps along with special syringes, stereotaxic frames, glass capillaries and needles. Here we will highlight seven microinjection pumps. The setup you choose depends on the size of injection aliquots, the volume to be injected and the size of needle or glass tip chosen. The products described below are listed in order by the smallest volume they can inject. See the comparison chart below or the links for additional information.

NanoFilTM

NanoFil, combined with and RPE or I/O kit, is the world's smallest dead volume (2.7µL) injection syringe system when the 10μL NanoFil syringe is used with WPI needles 33-36g.

. It can be operated by hand or used with the MMP, DMP or UMP3 pumping systems. The RPE and I/O kit contains Silflex tubing that has 2.74µL dead volume. The NanoFil with a needle has a dead volume of the needle which can be as low as 1.5nL. It is excellent for low volume injections and syringe filling when back filling is undesirable. A common application is ocular injections. Two syringes are available (10µL and 100µL), and the syringes can be adapted to Silflex tubing. Silflex is a plastic-coated glass tubing that is flexible and durable. It has a tiny diameter for low volume. It is 35cm long and offers some freedom of movement when performing injections by hand. Other options for NanoFil include the two injection kits, IO-KIT for inter ocular injections and the RPE-KIT for retinal pigment epithelial injections. 

 

Pneumatic PicoPumps

PV820 and PV830, pneumatic picopumps, were designed to simplify intracellular injection. You get repeatable microinjection in volumes ranging from picoliters to nanoliters. PV820 offers eject and hold pressure. The hold pressure prevents backfilling of the pipette by capillary action. In addition, the PV830 also has vacuum pressure which allows you to securely hold a cell with one pipette while you inject it with another. The volume injected is controlled by the inside diameter of the glass tip, the pressure and the time. This pump can inject fluids in the picoliter to microliter ranges.

 

Nanoliter 2010

The Nanoliter 2010 system is perfect for oocyte injection and applications in the 2.3–69nL range. It offers fast, accurate  2.3nL aliquot injections. It works with glass pipettes. It is back filled with oil, the oil is nearly pressed out, and then it is front filled with the injection fluid. The maximum volume is limited by what the glass pipette can hold. Nanoliter can be combined with the Micro4 controller.

 

UMP3

UMP3 was the first micro syringe pump on the market, and design improvements ensure it remains the best choice for stereotaxic brain injection applications. It is a motorized syringe pump that accepts syringes from 0.5µL–1mL. Using a 10µL syringe, the actual, minimum volume is 5–25nL. For intuitive, intelligent control, the UMP3 is combined with the Micro4 controller. It is built with extremely tight tolerance for high accuracy. It can be attached to the M3301 manual micropositioner, the DC3001 motorized micropositioner or any manual stereotaxic manipulator.

 

Manual Microsyringe Pumps

The MMP and DMP systems are manual microsyringe pumps. They use a manual micrometer to eject the fluid. The DMP micrometer has a digital display. Both use glass micropipettes. These are simple, hand operated systems for perfusion or withdraw of fluids.

 

Dual Microiontophoresis Current Generator

SYS-260, the Dual Microiontophoresis Current Generator, is an electrically isolated, battery-operated instrument designed for the electro-iontophoresis of dyes, drugs and charged substances from micropipettes. In ordinary use, the two current generators are operated in parallel providing two distinct currents; one for preventing substances in the micropipette from outward diffusion (the retain or hold current) and the second for actively ejecting charged material. 

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For more articles on Microinjection, refer to the following articles:

Comparing WPI Pumps

Description Application Needles
Glass
Inject Volume
Benefits
NanoFil
Smallest dead volume injection syringe Low volume injections (for example, ocular injections)     Smallest dead volume
Durable, flexible
Needle sizes from 26–36 ga. Blunt, sharp or beveled
Use it to move fluid into needles to get rid of air space and bubbles.
Options: Pump by hand or with the MMP, DMP, UMP3
PV830
Pneumatic picopump with vacuum pressure Intracellular injection (pL range)   Picoliter to nanoliter range Injection volume depends on tip ID, pressure and time.    Very small cell injections
Needle tips (glass) down to 0.1µm.
Hold a cell with one pipette while injecting with the second
PV820
Pneumatic picopump Intracellular injection (pL range)   Picoliter to nanoliter range Injection volume depends on tip ID, pressure and time.    Very small cell injections
Needle tips (glass) down to 0.1µm
Nanoliter 2010
Micro-processor, piston displacement injector Oocyte injection   2.3–69nL (Volume available is limited to the amount the glass micropipette can hold)    Rapid injection of hundreds of samples with repeatability Highly accurate
Fixed 2.3–69nL aliquots (up to 5µL using the Micro4 controller)
UMP3
Motorized syringe pump Sterotaxic brain injection Practical: 5–25nL (using 10µL syringe) Pulse-free delivery
Simple setup
Crafted with fine tolerance specifications for accuracy
DMP
Manual micro syringe pump with digital micrometer Manual injection of small amounts 10nL–µL, depends on the syringe used Accurate, hand-operated
Accepts100µL-1mL syringes
Digital readout on the micrometer
MMP
Manual micorsyringe pump with micrometer Manual injection of small amounts 10nL–µL, depends on the syringe used Accurate, hand-operated
Accepts 100µL-1mL syringes
SYS-260
Dual microiontophoresis current generator Injection of dyes, drugs and charges substances from micropipettes     Electrically isolated, battery operated
For pipettes with sub-micron tips
±9V converted to ±100V without a transformer for quiet output

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If you have any questions regarding the microinjection, give us a call toll-free at 866.606.1974 (US only) or email us at wpi@wpiinc.com.