And one way to do it is to use a plasmid. But the way we're going to do it in this lecture is by using a different type of vector, the vector we spoke about previously known as a lambda phage. Remember, a lambda phage is a bacteriophage that infects bacterial cells such as E. Coli cells. And we can use the lambda phage to basically infect the bacterial cells and the bacterial cells can then replicate that DNA of interest. So in step three, we basically take cohesive ends and we add the cohesive ends onto the ends, the edges of these DNA molecules. So for example, we take this light purple DNA molecule that we isolated in step two, and we add these cohesive ends onto the end of the DNA molecule and then we insert it into a lambda DNA phage molecule.