I am at it again

More of my science-art. The first image is taken of a petiole stained with phloroglucinal at 10x. A petiole is the little stem at the base of a leaf- it contains the vascular bundles which bring water to the leaf (xylem) and export sugar from the leaf (phloem). Phloroglucinal is a dye which (when activated by Hydrochloric acid) turns lignin a bright pink color. Ideally, a stain of a thin petiole section would reveal the circular cross-section of the xylem (since xylem, unlike phloem, is lignfied tissue.) However, as you can see, my shot got a bit smushed - and only the side view of the xylem is visible. Those things which look like dark smudges should be clear views of the vascular bundle. Well, I'm still learning. The second picture is one of those bundles taken at a close magnification. Although you cannot see it in this shot - you can tell xylem from the side view because they have a curlique structure of lignin wrapping around them. It looks sort of like a stretched out slinky. The third shot was perhaps the most useful - since I actually managed to capture part of the palisade layer. The picture is of a leaf section. If you look carefully, you can see cells on the top-side of the leaf which are shaped a bit like tic-tacs. Those are the epidermal cells on the outside of the leaf. Next down are verticle cells which are at a right angle to the epidermal cells. These are the palisade cells. One of the traits which Lauren and I are interested in measuring is palisade cell thickness - although so far the shot above is the best one we have gotten - and it is too blurry to use for percise measurements.

More later...