So we see that the plasma also contains an origin of replication, as shown, as well as an antibiotic resistant gene that can be used as a marker in the way that we discussed earlier. But in addition to this, it also contains the beta galactose today's gene. This gene codes for an enzyme that breaks down sugars and can be used to give a distinct blue color when that enzyme reacts with a special analog molecule, as we'll discuss in a future lecture. Now, in addition, this plasma has also been modified, engineered in the following way. We essentially insert a small section known as a polylinker. And what a polylinker is, it's this region that we can cut by using restriction enzymes and we can place any type of DNA molecule into the polyinkerer by cutting it with a restriction enzyme.