Sunday, February 8, 2009

Monarch Butterfly Egg

Some science images are easy, and some are very complex. This is a scanning electron microscope image of a Monarch Butterfly egg case is a very difficult picture. Just the sample preparation of this image took over a week. For years I have collected butterfly eggs, usually for my young kids. We will have a bottle with several eggs that hatch into microscopic worms that feed on milkweed leaves. In this case my kids and I went for several hikes in the finger lakes region of New York. After a few hours of looking on every milkweed plant we saw, we were able to find three eggs. The eggs were placed in a dilute solution of alcohol and the alcohol solution was slowly increased in strength until it was at 100% - a week later. The egg is then placed in a high pressure solution of carbon dioxide gas to remove all the water. This process is called critical point drying. The egg was then coated with a conductive layer of gold in a sputter coater. At this point the egg is ready for the scanning electron microscope (SEM). Since the microscope only collects a black and white image, the image needs to be colorized using Photo shop. The coloration process itself can be very complex. For this egg image I used two different images – one image contained the red part of the image, while the send image contained the blue data.


braenz said...

Hello Ted

What a fantastic photograph - and very interesting to hear how this was done.

Do the eggs of various species differ greatly?


PS Would you please email me; I think you can see my email address, or jacqui@ the above domain name also works.

Lilly said...

Thank you for the beautiful picture of the egg. Residents of the our assisted living are enjoying "raising" monarchs this year. However, no one could see the eggs or the little caterpillars. Now they have a chance to see them!