microINJECTOR™ System

MINJ-1:  $643.24 - Ships in 1-5 days


Pressure options

Power Options

Pulse Control Option

Needle Holder

Tritech Research has designed a microinjection system that lets you control with exacting precision both the pressure and the duration of the microinjection pulse. And, it's available at a fraction of the cost of competing systems.

Our microINJECTOR™ System uses a precision pressure regulator and a high-speed electronic solenoid switching valve, yet it is amazingly robust and simple to operate. It allows you to start and stop injection within a fraction of a second and control the quantity and flow of material into your target with precision. Our electronic foot control is designed to keep your hands free so you can concentrate on the manipulation of your needle and target.

The microINJECTOR comes preassembled, ready to use. You need only to attach the system to a compressed gas tank (e.g. N2) or in-house pressurized air line at one end and your needle at the other. You set the desired pressure and the system delivers pulses of pressure to your needle. In the base model, the duration of the injection pulse is controlled by how long you hold down the high-speed electronic foot pedal. With our easy-to-use, reliable equipment there is no "magic" required. Even a novice will be turning out transformants the first day.

The Single-Pressure MINJ-1, shown, switches between the injection pressure, during injection, and atmospheric pressure between injections. The Dual Pressure Option allows the user to apply a secondary, adjustable positive holding pressure to the needle between injections. This balance pressure is lower than the injection pressure but higher than the atmospheric pressure in the room. It can prevent backflow of media or cytoplasm into the needle, reducing sample dilution and needle clogging, respectively. Click HERE to see a photo of the Dual Pressure MINJ-1 or HERE to see the more compact low-input-pressure version of the Dual Pressure MINJ-1.

With our optional electronic MINJ-2 Pulse-Length Control Module (PCM) you can set injection times from ~0.1 to ~15 seconds. Each time the pedal is pressed, a constant volume is reproducibly injected. This option is crucial for quantitative experiments such as transient expression assays following microinjection of DNA, RNA, protein or other substances. For manual control, just set the time to maximum, and stop pushing the pedal early!

By controlling the pulse length and pressure independently, you can compensate for the flow characteristics of individual needles; you can determine if the needle is properly placed prior to any appreciable damage occurring to your target; and you can fill your target incrementally. High pressure settings with rapid on/off pulses aid in unclogging needles. The MINJ-2 is required for all orders to countries that use 220-240 volts, as the means of powering the MINJ-1.

As an added option to the microINJECTOR System you can hold your target with our state-of-the art MINJ-3 Holding Pipette Controller (HPC). The HPC allows you to pick-up and hold your target with vacuum suction and then release it with positive pressure. Our unique pneumatic foot pedal control allows a continuous range from vacuum through positive pressure depending on the position of the pedal. It is ideal for holding and manipulating targets such as embryos and oocytes. It is lso useful for injecting ES cells into Blastocysts. As any of our customers will attest, within a short time you will be proficiently getting transformants.

The output of the microINJECTOR needs to be coupled to something. For example, if you're using glass microcapillary needles, our MINJ-4 microINJECTOR™ Brass Straight-Arm Needle Holder will do the job cost-effectively.

A special version, the MINJ-4FEM, is designed for those that prefer to use Eppendorf® prepulled Femtotips® (that screw on) instead of our own lower-cost MINJ-PP prepulled needles that are compatible with our standard MINJ-4.

Another special version, the MINJ-4SLIP, is designed for those who prefer to use SlipTip® and Luer-Lok® Needles (that push or twist on) instead of our MINJ-PP glass needles.


Q: How do you connect the MINJ-1 microinjection system to a N2 or compressed air outlet instead of a high-pressure N2 tank?
A: If you are ordering a new system exclusively for use with a lab gas get, choose the Low Pressure Air Line Regulator under the regulator pull-down menu in the gree Options box above. This regulator comes with a quick-connect for 1/4-inch (6mm) Outside Diameter tubing.

You can also adapt and existing high-input-pressure system to work with a gas jet via a tubing connection to the regulator instead of using the cylinder fitting. The cylinder fitting can be unscrewed from the regulator by using a wrench on the flat part of it and unscrewing it counter-clockwise. That will expose a 1/4 NPT female port. We have a tubing quick-connect fitting that will screw into that port, or you can get any fitting you'd prefer. Our item number for the quick-connect:

MINJ-14NPT14QC: 1/4 NPT Male to 1/4 inch O.D. tubing Quick Connect fitting (special order - not on website, usually in stock) Please call or e-mail and we'll be glad to get you the fittings needed so that your system is ready to connect to what you have available.

This fitting accepts 1/4" outside-diameter tubing. We have the tubing, as well:

TT-1-4OD: 1/4" OD / 1/8" ID Clear Polyurethane Tubing

Q: Can the MINJ-1 deliver volumes in the picoliter range?
A: The MINJ-1 has no problem delivering volumes in the picoliter range. The delivery range is based on the needle tip diameter along with the pressure and time. Sharp needles with tips in the 1 micron range easily deliver picoliter volumes.

Q: Do you have adapters or setups that could split, let's say a single compressed air faucet, into 4, 6, or 8 MINJ-1 injection stations (15-20psi each)? Do you recommend any portable, electric air compressors?
A: Yes, we have Quick-connect Tee fittings that can split one pressure source to several of the MINJ-1 low-input-pressure-version units. We have an adapter that replaces the barb output from the "standard" compressed air faucets with a 1/4" tubing quick-connect, which would then have a piece or tubing going to the Tee(s) where it will be split into the MINJ-1 units.
We do sell a relatively portable and relatively quiet (56dBA) oil-free air compressor that could serve as the pressure source when there is not compressed air faucet available. It could go under the lab bench with the output tube coming up. Not only is it quiet, but it will not even turn on very often because the MINJ-1 uses so little air per injection. The product number is MINJ-CMPR1.

Q: Can the MINJ-1 be used to inject larger volumes into adult flies?
A: Yes, the MINJ-1 can be used to inject adult flies. You will need to ensure you have the appropriate needle tip to get the flow needed and the appropriate amount of liquid in your needles. This way you can get the larger amounts injected to come out in a reasonable amount of time. If the volumes are larger than several nano liters, you might want to draw lines on your needles at 1 uL to 0.1 uL increments so you can see how much you are injecting.

Q: The needle on our MINJ-4 tends to vibrate and move forward when pressure is applied during injections. How can this be fixed?
A: The issue is that the needle is probably not being held securely by the compression fitting. Please see the photo on our MINJ-4 page that shows the correct order and orientation of the parts that are inside the end of MINJ-4, and ensure you have all the pieces. The idea is that as the large nut is tightened, the rubber compression fitting is squeezed between the needle holder body and the small brass ferrule. This causes it to thicken and grab on to the glass. It should be able to grab well onto glass from 1.0mm - 1.5mm outside diameter. If it is the right tightness and the pressure is not too high (perhaps under 30 psi) then the needle shouldn't move much during the injection pulse.

Q: How can the 1/4 inch tubing be attached to a laboratory hose barb output?
A: For connection to lab air jets, we recommend our fitting MINJ-38NPT14QC. This fitting screws into a female 3/8 NPT thread on one side and the other side allows for secure connection to the 1/4" OD tubing of the MINJ-1 or MINJ-D. Please ensure that the thread size is the same as your lab gas output. Our MINJ-38NPT14QC is meant to replace the hose barb / white portion of your gas fitting. The thread size of our MINJ-38NPT14QC fitting is a 3/8 Male NPT, so it will be compatible with a female 3/8 NPT thread. If this fitting is not compatible, you could consider making an adapter from a small piece of stretchy tubing and 2 hose clamps. One end of this tubing can be clamped onto your lab hose barb output, and the other end can be clamped with the 1/4" OD microinjector tubing inside it to form a bridge.

† These are our list prices. If you are paying with an Institutional Purchase Order or by check, you qualify for a 7.5% discount. Click here to change your payment method and see the lower prices.