Happy Friday (or should we say, Fri-YAY) from CauseScience!
psgurel– Today I am miniprepping! If you remember last week, I was doing PCR to get a specific DNA construct. After doing PCR, there are several steps before you have nice clean DNA. For the DNA I’m using (plasmid DNA) the final step is to extract your DNA from bacteria. Lucky for us, several companies make “miniprep” kits that make this process super quick and easy. It takes about 30min, and then you have (hopefully) nice, clean DNA!
crestwind24– This is crazy! I am also doing mini preps of DNA this morning!! SAMESIES!! Preparing DNA is a major part of most labs, as made obvious by todays post. I am making DNA that will label synapses in neurons in C. elegans. Once I have the DNA that I want, we will inject it into developing embryos, and then I will have transgenic worms!! Hopefully with glowing synapses!! This will allow me to visualize connections between different neurons.
CauseScience Friday… more like mini prep Friday!!!
psgurel – I’ve just spent most of my morning in lab meeting, and will spend my afternoon going to a few lectures. Presenting work and getting feedback is a critical part of science. Lab meetings are somewhat more informal sessions where the entire lab can get together and discuss specific details on members’ projects. It’s helpful for all involved in terms of troubleshooting, fine tuning direction of the research project, etc. It’s fun, but can also be somewhat tiring. Here’s my post lab meeting selfie 🙂
crestwind24 – This morning I came into lab very early to make sure I got all of my experiments done before heading to Philadelphia in the afternoon. One of the things I needed to do was run 4 PCR reactions and then image the products of the reactions using gel electrophoresis. Or more simply, I needed to make specific fragments of DNA from the C. elegans genome, and then make sure I made the correct DNA by looking at its size. When I visualized the PCR reactions separated by size on an agarose gel (top panel), I did not see the size DNA I was making with the PCR. Instead I saw a bunch of randomly sized bands and smears (hence my grumpy face when sitting at the gel imager, bottom left). Luckily, since I was in lab so early, I redid the PCR at a different temperature and got nice crisp bands at the exact size I expected (right bottom panel)!!! I love when molecular biology works!!!
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 StainElectron 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!