The main event, science-wise, this week was a two-hour session on the scanning electron microscope. I looked at the first stub of the “Ample Samples” described earlier. This proved spectacularly disappointing. Well, ok, ‘spectacular’ is an over-statement, but disappointing sure enough.
The stub had five sections, one from each of the genotypes being studied. I started with the ‘A’ section (why not?). I found the fiber cells where I expected them, based on the organ histology, and they were nicely cut open, again as expected. But utterly unexpected, I saw cell walls covered by glop (Figure 1). I think the glop in question here is leftover pieces of the plasma membrane. In most of the images, there was so much membrane glop the cell wall was invisible. Like the streets of Washington DC this weekend, under snow.
I looked up and down on the ‘A’ section and glop coated the cell walls of every fiber cell I checked, to a greater or lesser extent—mostly greater. Same story for ‘B’ section, and for ‘D’. I ran out of time for ‘E’. But treatment ‘C’ looked perfect, just like the sections did last fall when I was working up a good method (see Jan 3rd post). The sections in ‘C’ also held together during processing better than any of the other letters. I guess ‘C’ is the wild type, for which our method rocks. But for the mutants, the method failed. Evidently, their plasma membranes stick to their cell walls. Now this is “interesting” in the sense that it is apparently a common effect, or phenotype, of the mutations. But it is a right pain because it prevents me from imaging their cell wall, which is what. I. am. trying. to. do.
So all those ample samples are worthless. Fun times. Now Joseph and I have to do more troubleshooting, this time on a mutant to figure out how to disglopify the sections. Probably not too hard, a little soap and salt, or perhaps even stronger stuff. We’ll use the gentlest thing we can do to clean ‘em up. Stay tuned!