 Hello. Today, we're going to go over protein electrophoresis. The last time that we met, we went over DNA electrophoresis and talked about how negatively charged DNA migrates toward the positively charged anode. When we get into proteins, we see that proteins are a little bit more difficult because of their structure. Proteins are anphoteric in nature, meaning that they have both properties of acids and bases, meaning that they can accept or donate electrons based on the buffer that surrounds them. So with proteins, we have to take an extra step to make sure that we are all starting on the same base. We have to make sure that everything has the same charge so that we can separate based on just size. For this reason, we have to examine isoelectric point. And this is going to be the pH in which the charge is going to be neutral. So if we have a pH that is going to be high, then the protein will be negative in charge. And that's what we need to look at doing to make sure everything has the same base charge so that we can separate solely on size. So what we're going to use today is called SDS page. SDS page stands for sodium dodecal sulfide polyacrylamide gel electrophoresis. And you don't need to know all that, but I did want to let you know what that acronym stands for because a lot of people are curious. So what we're going to do today is SDS page, which is going to use the buffer that is going to convey a negative charge toward your proteins. We're going to use the sodium dodecal sulfate to break up the proteins into fragments and then separate those fragments with the same sieve-like material that we used previously, except we're going to use your polyacrylamide instead of agarose. It does work on the same basis where things that are bigger travel a shorter distance versus things that are smaller are going to travel much further in the medium. Today we're going to be using our BioRad ready gels, which are perfect because they come already made. And it's going to be a lot easier for us to save time and energy. So let's get started.