Dear Evol-members,
Thank you very much to all of you that sent me suggestions about your
experience with automated DNA extraction machines and tissue
homogenization.
Below, I copy the answers and my original question.

Best,
Romina

My original inquiry:

Dear members,

I´ll be happy if any of you can give some piece of advice about your
experience with equipments for automated DNA extraction (like Promega's
Maxwell 16 System) and systems to destroy hard tissues. We are currently
working with insect legs and manual homogenizing is far from efficient.

Thanks in advance.
Best wishes,
Romina

---------

Answers:

1) Hi Romina - If you are looking for an inexpensive way to go - check our
hour
homemade version, very easy to make and extremely effective.

For the earliest and rudimentary version see -
http://www.polyploid.net/machacadora/machacadora.html

Donovan

2) Hi Romina,Your email was passed onto me from Professor Wetherall.  For
hard tissues like insect legs or whole insects we use a method called ANDE
which has been used by several agricultural labs for nondestructive DNA
extraction for PCR purposes only - it is not suitable if you want good
quality DNA.

more information can be found at http://www.ande.com.au/

regards

David

3) Dear Romina

We extract from insects using the qiagen blood and tissue kit (both tubes
and 96 well plates), but have used a variety of kits.  Presently we also
use a plate extraction kit from zygem.  We do not homogenise tissue – we
incubate either whole insects, or parts of them (e.g. legs) in the
extraction buffer with proteinase K, and then remove the body parts before
continuing with the extraction.  This works fine, thus there is little
need for you to homogenise tissue.

Cheers
Brent

4) Hi Romina,
We used qiagen animal tissue extraction kit. It works well with insect legs.

Qixin

5) Hello Romina,
In response to your email below :  we use a TissueLysser from Qiagen, and
to extract DNA and RNA from leaf tissue it is very efficient...

Best wishes,
Raquel Carvalho

6) Hi Romina,

I work on ants, and we homogenize using an electric power drill that
you can buy in a hardware store.  Just stick in the usual pestle
instead of the drill bit, and you're set to go.

We are using the Qiagen kits, which work very well.

best,
Beth

7) Hi Romina
In plants, we freeze the tissue in liquid nitrogen, and grind by adding a
metal bead and shaking.
This should work with insect parts too

You can do this in 96 well plate format using the Geno/Grinder 2000 (or
newer 2010 version) or the Qiagen Tissue Lyser

These machines don't do the DNA extraction, but just grind the tissue.
It works with very hard tissues and takes about 5 minutes or less

diana

8) Dear Romina,

In our facility we use Biomek FX robot for semi-automated DNA extraction
(elution is done manually, to minimize chances of contamination). Please
find attached my papers and detailed protocol for DNA extraction which is
suitable for insects. For insects you don't actually need tissue
homogenization, simply use overnight incubation at 56C.
Biomek robots are quite sophisticated, but the software is intuitive.

For plants we use similar protocol (see attached paper), but use Tissue
Lyser and stainless steel beads for grinding.

Please let me know if you have more questions.

Best regards,
Nataly

9) Dear Romina

I tested the Maxwell 16 on tough Eucalyptus leaves and it did not crush them
very well.  The Retsch mixer mill works well for most eucalypt leaves though
(after they have been frozen in liquid nitrogen).

The Promega reps (at least in Australia) are very nice and might lend you a
machine and give you a kit to test the protocol in your species of interest.

Good luck
Rebecca

Dra. Romina Piccinali
Laboratorio de Eco-Epidemiología
Facultad de Ciencias Exactas y Naturales
Universidad de Buenos Aires
Argentina
Tel/Fax +54-11-4576-3318
E-mail: rpicci@ege.fcen.uba.ar

rpicci@ege.fcen.uba.ar