In article <3nk18p$437 at bigbird.csd.scarolina.edu>, Richard Vogt
<vogt at biol.scarolina.edu> wrote:
> I just received money to purchase an injection setup, and I have been
> receiving requests for advice on same. I would appreciate some
> suggestions on desirable pressure injectors, manipulators and minimal
> scope needs (eg. inverted, dissecting, etc.).I know some of this
> is described in "The Book" and "Monitor", but I would nevertheless be
> interested in some additional comments/attitudes.
>> I'll post a summary on my www server (zebra.scarolina.edu).
You haven't quite given enough info -- the setup depends on what you are
injecting, and in particular what age animal you are working with.
My main setup is a Nikon upright with a stage-mounted hydraulic
micromanipulator. For single-cell injections at late stages (anything
from late gastrula to embryos) we use this rig with a 40x water
immersion objective and DIC. You really need at least that level of
magnification if you want to pop into small, single cells accurately - we also
have a 2x optizoom on the scope to give us a little more mag.
For blastula injections, we can use the same apparatus, but we use a
much lower mag, 4 or 10x. Lately, though, we've found we can be a lot more
crude...we can inject animals on the dissecting scope, just holding the
electrode holder by hand and stabbing away. It's fast, cheap, and fairly
easy, although you can't have too much coffee prior to the experiment.
You haven't said what you'll be injecting. For most fluorescent dyes, we
iontophorese using a WPI current programmer. That box has a lot of nice
knobs and dials, but I think it is overpriced at $1500. Bill Trevarrow
told me he got the same functionality out of a 9V battery, a couple of
resistors, and some duct tape; it may be a matter of style.
We also do pressure injection, using a really nice box from ASI. We just
tap into house air, set a knob to give us a couple of psi for a few msec,
and use a footswitch to spritz away.