How to Preserve Insects with Glycerin

Heat your glycerin to reduce its viscosity. At room temperature, glycerin is very thick and viscous and will be difficult to pour; it freezes at 64 degrees F. Heat it over a very low flame so it pours easily. Placing your specimens in overly hot glycerin can damage them, so try not to heat it beyond 100 degrees F.

Use a pipette or baster to add glycerin to a specimen bottle until it is about 1/4 filled. The size of the specimen bottle you use will depend on the size of your specimen. Most scientific supply companies sell specimen bottles of various sizes.

Gently grasp your insect specimen with forceps and lower it into the bottle so it just touches the glycerin. You will probably want to have the specimen suspended in the center of space within the bottle, so it will need to be held there while you fill it the rest of the way.

Add more glycerin, while holding the insect specimen in place, until the specimen is completely covered. Avoid filling the bottle to the rim because the glycerin will need a little space to expand and contract.

Hold the insect specimen in place until the glycerin becomes cool enough to let the insect go without it shifting within the liquid. You should not have to hold the specimen for longer than a few minutes.

Cover the bottle with a an elastic or moldable film. A rigid covering like a stopper or cork might be ejected by internal pressure if the contents of the bottle become heated.