Now, this DNA primer with that mismatched base, also known as a point mutation, can now be used to synthesize the protein of interest, as we'll see in just a moment. So this base pair mutation is known as a point mutation because we essentially mutate our base at a single point, we exchange an A for C. And that's exactly why we call this site directed mutagenesis, because we make this point mutation at that single site. Now, the reason we also call it a ligonucleotide directed mutagenesis is because this DNA primer that we create in this particular case, it consists of these 50 nucleotides that describes an oligonucleotide molecule. OligA simply means we have about ten to 20 to 30 of these nucleotides found inside that DNA molecule. So we synthesize an artificial oligonucleotide in the lab, and then we change the sequence ever so slightly to basically accommodate a codon that will create the aspartate instead of glutamate. Now, let's actually take a look at the following three steps that we have to follow to basically form that protein that will contain the aspartate instead of the glutamate.