crestwind24: Today I am doing PCR to amplify a gene I am interested in from the DNA of a worm (C. elegans). PCR, or Polymerase Chain Reaction, can be used to make DNA, check for the presence of DNA, and/or sequence DNA. PCR is commonly used to detect the presence of viruses, like Ebola, by looking for the DNA of the virus in the patient’s blood or bodily fluids. Setting up a PCR involves pipetting small volumes of liquid, containing DNA, enzymes, salts, etc into tiny tubes (see images). Then the tubes are placed into a cycling machine (ours is named Cycle Jackson… get it?) that changes temperature over and over in a cycle to activate the enzyme that makes the DNA. At the end I hopefully will have a bunch of the DNA I want!
psgurel: Today I am staining grids for Negative Stain Electron Microscopy. I will be using the TEM (Transmission Electron Microscope) which essentially uses a high voltage electron beam to visualize samples. My samples are placed on tiny grids (the arrow in my picture) and then stained with uranyl acetate, which is slightly radioactive (hence why I have to wear a lab coat) and scatters the electron beam. As a result, my samples stained with uranyl acetate will not absorb electrons and thus I can visualize them in contrast to the grid surface which will absorb electrons. Why use TEM instead of other types of microscopy? A typical fluorescence microscope yields about 200nm resolution. However, I’m trying to visualize protein clusters of less than 100nm in length…about 10,000x smaller than a grain of sand! The TEM will be able to resolve these structures!