Adventures in Staining
Recently I have been trying to sort out staining problems with some of my TEM specimens, and today I got farther along with that. Normally, we prepare specimens without stain, and stain them after cutting them and mounting them on grids. The specimens that I have been looking at lately were prepared by another lab, though, and they included some stain (uranyl acetate, which primarily stains proteins and nucleic acids) in their preparation. We are not quite certain how to deal with this. I had already stained all of the grids with half our normal amount of uranyl acetate. Today I stained two grids with more uranyl acetate (bringing them up to our usual amount, exclusive of the pre-existing stain), and one of the two with the other stain that we use as well (lead citrate, which primarily stains membranes and nucleic acids). Oddly, the latter treatment seemed to make the proteins stand out more, although still not enough to make us happy. Frustratingly, I was not able to put the images that I took on my flash drive, as the computer did not want to recognise it, but I will show it to my advisor one way or another eventually.
I also made media. This is normally a fairly drawn-out process, as the necessary filtration stage is extremely slow, but it was made even longer today by my using up the last of a jar of Cerophyll, which meant that there was even more small particulate matter to clog up the filters than usual. Nevertheless, I got the job done, even if it did mean leaving late. Leaving late has rarely been a problem before!
I also made media. This is normally a fairly drawn-out process, as the necessary filtration stage is extremely slow, but it was made even longer today by my using up the last of a jar of Cerophyll, which meant that there was even more small particulate matter to clog up the filters than usual. Nevertheless, I got the job done, even if it did mean leaving late. Leaving late has rarely been a problem before!