Tissues were immersion fixed in modified Karnofsky's fixative in cacodylate buffer, osmicated and en block stained with UA. After dehydration in ethanol, the tissues were infiltrated with increasing concentrations of LX112 in propylene oxide. Thin sections were cut on a Reichert Ultracut E, picked up on formvar coated grids, and photographed on a JOEL 1200EX TEM. For each image, two negatives were combined. They were first scanned using an AGFA 2500 flatbed scanner, then made into seamless images using Photoshop. I personally completed all steps involved.

The lower image shows the canaliculi by TEM. In this image you can see that the dark spots seen in the LM image are two different structures; mitochondria, and vesicles containing crystalline arrays. Although these crystalline structures were seen in all my embedded samples, Dr. Gildow, my co-advisor, had only seen them occasionally in his samples. We were not able to positively identify this substance. Unfortunately, the opportunity to test my personal theory on the chemical make-up of these structures never arose while I was at PSU.

The top image shows an aphid (S. avenae) in a feeding chamber, where there was unlimited access to food laced with dye. The red spots are excrement of the insect, stained with dye. Exuvia are the cast skins of the insect. The container is made from a styrofoam 15ml tube rack, and sheer curtain material.

The lower image is a manual dissection of S. avenae, showing the digestive track. This was done to look for permanent effects of the ingested dyes.

Both images were taken on a Zeiss SV11 dissection microscope.