WPI or Femtojet for Viral Injections?

Anyone have any preferences on injectors for viral injections into the spinal cord and brain? I used the popular WPI UMP4 micropump this summer. It worked, but it requires one to fill a Hamilton syringe and glass pipette with mineral oil all the way through in order to maintain pressure throughout the whole setup.

I’ve seen some papers using a pressure injection system, namely the Femtojet (Eppendorf). This looks attractive because it doesn’t require the filling of oil or other liquid. But I don’t see it used as much. Anyone have any experience?

http://www.ncbi.nlm.nih.gov/pubmed/26387932 (femtojet)

@cedric.peirs @RPSeal @SamineniV @liz

We use the WPI UMP3 in our lab, which I’m assuming is just an older version of the UMP4, with a Hamilton syringe. Instead of using the glass pipette + Hamilton syringe combo, we simply use a small-volume (2.5ul) Hamilton syringe with a removable 28 or 33 gauge needle (also from Hamilton). I’m not sure the removable needle would work in the spinal cord, since 33 ga might still be too large, and you may want the precise tip shape that you would be able to achieve by pulling your own glass pipettes. But for brain injections we routinely use the removable needle with injection volumes of 100-1000nl.

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Thanks @liz. Yes for the brain, I’d just use one of those removable needles that come with the Hamilton syringe. But I think they are too big for the cord. I see brain people use those all the time and they don’t mess with the glass pipettes.

I wanted to follow up on this. I did a demo of the Femtojet a while back. I thought it was going to work really nicely since you can control the pressure and you don’t need to put any oil or anything to backload. It was actually still very hard to control the flow rate and also to get consistently get the same needle size, which greatly affects the parameters. So my conclusion is, stick with the WPI or similar mechanical pump.

Sorry to resurrect such an old thread, but we recently started using the WPI Nanofil system in our lab with excellent results. To me it’s the best of both worlds because you can get a very fine needle (up to 36g although the maximum we tried was 35g) that is similar in size to the glass micropipette, but you don’t have to backfill with mineral oil. It’s also compatible with our existing UMP3 injector, which is convenient.
Members of our lab have used this setup to do intraspinal injections in ~P21 mice, for which our typical Hamilton needles are too large.

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That’s fantastic Liz! Wow. Thanks for sharing. I’m going to have to look into this. I hate backfilling those glass pipettes.

@SamineniV