Introduction to DNA Cloning: Videos & Practice Problems

DNA cloning is the process of creating multiple identical copies of a specific DNA sequence, often using bacterial cells like E. coli as hosts. This involves biochemical reactions to produce the desired DNA, which is then inserted into the host cell for replication. Recombinant DNA, a molecule containing DNA from two different sources, is crucial for genetic experiments. Bacterial plasmids serve as cloning vectors, carrying foreign DNA into host cells, allowing for the amplification of genes of interest through normal cellular replication processes.

Introduction to DNA Cloning

In this video, we're going to begin our introduction to DNA cloning. And so DNA cloning is really just the process of creating many identical copies of DNA. For example, a gene inside of a cell, like, for example, a bacterial cell like E. coli, as you can see down below in this image. And so there are a series of biochemical reactions that researchers can use to produce DNA containing a specific sequence of interest, and we'll be able to talk a little bit about these biochemical reactions as we move forward in our course. Now the DNA with the specific sequence of interest, once it has been produced, it can then be transferred into a host cell. And the host cell can then replicate via its normal process and then the specific sequence of interest can be cloned many times or replicated many times. And so if we take a look at this silly little cartoon that we made down below, notice over here on the far left-hand side we have a scientist, and this scientist has made a specific DNA molecule with a specific sequence of interest, which is here in orange. And so notice that the scientist is saying, hey, I made this for you, saying this to the E. coli, the bacterial cell over here, and this guy, this bacterial cell is saying, oh, for me? And so basically what can happen is this DNA, which has the specific DNA sequence of interest, it can be inserted into E. coli. And when the E. coli replicate via their normal process, they can also clone the DNA, and this is the process of DNA cloning. And so notice that you can get a lot of replicated DNA and a lot of that specific gene or sequence of interest, just through DNA cloning. And, again, it's going to be utilizing living cells. DNA cloning utilizes a cell as indicated up above. And so as we move forward in our course, we'll be able to talk more and more about DNA cloning, but for now, this here concludes our introduction to DNA cloning, and I'll see you all in our next video.

Cloning with Recombinant DNA

In this video, we're going to talk about cloning with recombinant DNA. And so scientists tend to create and clone recombinant DNA for genetic experiments. But what is recombinant DNA? Well, recombinant DNA is really just a molecule that contains DNA from 2 different sources, and these two different sources are often going to be different species. For example, a bacteria and a human. And so bacterial plasmids are going to be very, very important for this lesson. And bacterial plasmids are small, circular DNA molecules that are replicated independently from the bacteria's or the organism's genome, and these bacterial plasmids, these small circular DNA molecules, they can be used as cloning vectors. And cloning vectors are molecules such as plasmids that are capable of carrying a gene of interest, like foreign DNA, into a host cell. And so in our example down below, we're gonna be talking about creating recombinant DNA plasmids to be used as cloning vectors. And so, in this image down below, notice over here on the left-hand side, we're showing you the bacterial plasmid, which is this circular, small circular DNA molecule found in bacteria. And then we're showing you a gene of interest here, which could be from a different species, like for example, a human. And so this is DNA from 2 different sources, the bacteria and the human. And so we can create a recombinant DNA molecule, and the recombinant DNA molecule is gonna be a single molecule that has DNA from 2 different sources. And in this example, the recombinant DNA has DNA from the bacterial plasmid, and it also has the gene of interest, which would be from a different species, like, for example, a human. And so you have a single molecule that has bacterial DNA and human DNA. A single molecule with DNA from 2 different sources would be a recombinant DNA molecule. And this recombinant DNA molecule can serve as a cloning vector. And cloning vectors are just, molecules or plasmids that will carry a gene of interest into a host cell. And so this recombinant DNA can be used to carry the gene of interest here into a host cell, like bacteria host cells. And so here we have a few different bacteria here that all have the recombinant DNA molecule and all have the gene of recombinant DNA molecule and all have the gene of interest. And so in other words what we're saying here is that cloning vectors are forms of recombinant DNA that carry the foreign DNA into the host cell. And once the foreign DNA is in the host cell, it can be replicated by the cell, when the cell goes to replicate itself. And so this is something that we're gonna talk more and more about as we move forward in our course. But for now, this here concludes our brief introduction to cloning with recombinant DNA, and we'll be able to learn more and more about this as we move forward. So I'll see you all in our next video.

Small accessory rings of DNA that replicate independently of an organism's genome are called _____.

• A. Recombinant DNA.
• B. Plasmids.
• C. Clones.
• D. Transposons.

Answer: (B)

In DNA technology, the term 'vector' can refer to:

• A. The enzyme that cuts DNA into restriction fragments.
• B. The sticky end of a DNA fragment.
• C. A SNP marker.
• D. A vehicle used to transfer DNA into a living cell.

Answer: (D)

What is recombinant DNA made of?

• A. Restriction enzymes and target DNA.
• B. Target DNA and DNA ligase.
• C. DNA from two different sources.
• D. A bacterial chromosome and a bacterial plasmid.
• E. None are correct.

Answer: (C)

Here’s what students ask on this topic:

What is DNA cloning and how is it performed?

DNA cloning is the process of creating multiple identical copies of a specific DNA sequence. It involves several steps: first, a DNA sequence of interest is isolated and inserted into a vector, such as a bacterial plasmid. This recombinant DNA is then introduced into a host cell, like E. coli. The host cell replicates, producing many copies of the DNA sequence. This process utilizes biochemical reactions to produce the desired DNA and relies on the host cell's natural replication mechanisms to amplify the DNA.

What is recombinant DNA and why is it important in genetic experiments?

Recombinant DNA is a molecule that contains DNA from two different sources, often from different species. For example, it can combine bacterial DNA with human DNA. This is crucial in genetic experiments because it allows scientists to study genes in a controlled environment. Recombinant DNA can be inserted into host cells, which then replicate the foreign DNA, enabling the study of gene function, protein expression, and genetic modifications. Bacterial plasmids often serve as cloning vectors to carry the recombinant DNA into host cells.

How do bacterial plasmids function as cloning vectors?

Bacterial plasmids are small, circular DNA molecules that replicate independently of the bacterial genome. They function as cloning vectors by carrying a gene of interest into a host cell. The plasmid is engineered to include the foreign DNA, creating recombinant DNA. When introduced into a host cell, such as E. coli, the plasmid replicates along with the host cell's DNA. This allows for the amplification of the gene of interest, making plasmids essential tools in DNA cloning and genetic experiments.

What are the steps involved in creating recombinant DNA?

Creating recombinant DNA involves several key steps: 1) Isolation of the DNA sequence of interest. 2) Cutting the DNA and the plasmid vector with the same restriction enzyme to create compatible ends. 3) Ligation of the DNA sequence into the plasmid vector using DNA ligase. 4) Introduction of the recombinant plasmid into a host cell, such as E. coli, through a process called transformation. 5) Selection and screening of the host cells that have successfully taken up the recombinant plasmid. These steps result in the creation of recombinant DNA that can be replicated within the host cell.

What are the applications of DNA cloning in biotechnology?

DNA cloning has numerous applications in biotechnology, including: 1) Gene therapy, where cloned genes are used to treat genetic disorders. 2) Production of recombinant proteins, such as insulin, for medical use. 3) Genetic research, allowing scientists to study gene function and regulation. 4) Agricultural biotechnology, where cloned genes are used to create genetically modified crops with desirable traits. 5) Development of vaccines, where cloned DNA sequences are used to produce antigens. These applications demonstrate the versatility and importance of DNA cloning in advancing scientific and medical research.