Now, how exactly can we use the lambda phages as vectors? Well, it turns out that we can actually replace this DNA molecule with the DNA molecule of choice. As long as the size of the DNA molecule that we're essentially putting in is about the same as the size of this DNA molecule found in the lambda phage. So what that means is the lambda phage virus does not need its own DNA to actually survive. We can put in any DNA as long as the size it's pretty much the same as the size of that initial lambda DNA. So to see how we can actually do that, let's take a look at the following diagram.