Sunday, 2 June 2013

PhD week 65: DMHF

Male (left) and female (right) weevil parts mounted in DMHF.

The internal morphology of insects is a veritable gold mine of interesting characters. Obviously, in order to find investigate these characters it is necessary to dissect specimens. Unfortunately, this results in disarticulated beetle bits that one needs to store somehow in order to look at them again in the future.

The classic method of storing dissected materials is in very small vials that can be kept on the pin that holds the remainder of the specimen. This can be useful, but is a bit fiddly to remove the pieces from the vial when one needs to look at them again. In addition, it's become difficult to buy smaller glass vials, and I'm not a fan of the polyurethane vials that are readily available.

An alternative method that I've been exploring this past week is using the mounting medium DMHF. This mountant is soluble in water and dries crystal clear. The method that I've been using is to put a drop of DMHF on a card, immediately place the parts into the medium, add sufficient DMHF to cover the parts entirely, and leave for a couple of days to set. The card is then pinned below the specimen, and the parts are both protected and readily viewable (see picture above). I haven't tried it yet, but I understand that removing the parts is as simple as placing the card in a small dish of water and waiting a few minutes for the DMHF to dissolve.

A frustrating part of working with DMHF is that it forms a skin soon after exposure to air (c. 30 seconds). This skin can make it a little tricky to manoeuver pieces after placing them into the medium. After a little bit of experience though, one can usually get pieces in without needing to do too much messing around with them after the fact. I've had a positive first experince with the stuff, and am intending to carry on using it for the time being at least.


Websites:
Logic Matters
NetKnots—Tautline Hitch
Arctic Terns breeding in Netherlands migrate via Australia
LaTeX Stack Exchange: What fonts are installed on my box?

Listened:
Norma Jean—Disconnecktie: The Faithful Vampire

Watched:
Star Trek (Original Series) Season One

1 comment:

Erick O. Martinez-Luque said...

Muy interesante la t├ęcnica, me gustaria saber como hacer el DMHF, para probarlo en mis ejemplares, donde puedo consultar como hacerlo?