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Current time:0:00Total duration:3:22

Expressing cloned genes

Video transcript

not only when we think about cloning we think about cloning in this sense so let's say that we've got a baby and it's just so cute that we want two of them so we can go in a clone a baby well this isn't exactly what we're talking about when we talk about cloning in the scientific sense normally what that means scientifically is let's say that I've got a cell and there's a certain gene let's call it GNA for now and I want to clone that gene so how do I go about cloning gene a well the first step is to isolate the messenger RNA from the gene of interest so if we have the G messenger RNA what we need to do is we need to convert it into DNA so if we add reverse transcriptase reverse transcriptase which is an enzyme that will go and actually create DNA from RNA we'll end up with something known as complementary in DNA and complementary DNA and that's what the C stands for basically the complementary DNA sequence to the mRNA sequence now keep in mind that the complementary DNA only contains exon so the introns have already been spliced out and we talked about introns and exons in a earlier video so next what we have to do is we take this cDNA this complementary DNA and now what we want to do is we want to amplify it we want to create lots and lots of the complementary DNA so that we can have plenty of cDNA to work with so in order to do that we have to take this complementary cDNA and transform it into a plasmid now what does transform me well what it basically means is that we're taking the complementary DNA and we're basically putting it into a plasmid so we're going to transform it into a plasmid and this plasmid is going to contain antibiotic resistant genes so anti biotic resistant genes and we'll talk about why that's important in just a second so now that we have this plasmid we want to really infect bacteria with the plasmid so we want to put it into bacteria and once it's in the bacteria what we want to do is we want to actually add antibiotics to the culture of bacteria so we're going to add antibiotics and since the plasmid containing antibiotic resistant genes the bacteria that were successfully transected will survive and all the other ones that didn't have a plasmid inserted will die so now we've got pure pure culture of bacteria that all are all contain the plasmid which contains the gene of interest the DNA of interest and now the bacteria just does its thing so it's just going to start to replicate the bacteria is going to replicate and as its replicating it's going to produce lots and lots of the gene of interest it's going to produce lots of DM RNA of interest and basically what we just did through this process is we just cloned the gene of interest and that's what we're talking about when we're talking about cloning at least from a scientific point of view