Cell Culture

Hi in this video, I'm gonna be talking to you about cell culture. So what cell culture is is the process of growing cells in a laboratory laboratory setting? So this began in 1907. And there are really two types of cultures that cells can be grown in. The first is called a primary culture. And these are cells directly taken from tissue. So you have some type of tissue, a skin tissue or kidney and brain whatever. And you begin to dissect that tissue take apart the exercise or matrix. You cut the tissue into thin, thin, like extremely thin slices. And then you can extract those cells from those thin slices and actually grow them in a laboratory. Now you can imagine all of that processing is really harsh on these cells that aren't used to stuff like that. And so these cells, although very useful because they come directly out of individuals are hard to work with because they don't live that long. Um and they're really difficult to keep alive in a culture setting. So what researchers have done is created these secondary cultures and these are cells that are derived from other culture cells. So if you can keep these primary culture tissue cells alive long enough so that they can divide, then you can continue dividing those cultures if they're properly processed to create these cell lines. Now, cell lines are cells that have undergone some type of genetic modification, either by themselves or something as scientists has done to them and this allows them to grow indefinitely. So, can you think of maybe diseases for instance, that cell lines could come from? Can you think of any disease that is the result of cells growing indefinitely? Right. This sounds exactly like cancer. Right. So cancer is um you know, just uncontrolled cell growth essentially and division. And so cell lines are often driven from cancer cells or scientists have taken cells that aren't cancer cells and mutated them so that they can grow indefinitely. And generally if you were to put these cells into special type of laboratory mice, they would typically grow tumors. But although these can be grown indefinitely, they do, they are cells. And so cells don't live forever. Right? So they They usually die after about 25-40 divisions. And you say, Okay, well then why do you put that much time into creating these cell lines? Well, the reason is because when you have a cell line and it divides and divides a couple times, then you have a ton of sales. I mean you can have a dip like flask of cells after just a couple of division. And so you take those early dividing cells. The cells that only have a couple divisions and you can freeze them, you can freeze them at -80C, you can freeze them at liquid nitrogen and you can keep them essentially in liquid nitrogen for Forever. And when you saw those cells any time a year later, 10 years later, 50 years later they will just start dividing like they did before. So cell lines are super useful because you can have these cell lines that you freeze and then just use when you need them. But growing cells um requires because the cells require a lot of care when grown in a laboratory they have to have nutrients they would normally get in the body. Right? And so we provide that there's some type of media solution um They have to be grown usually on some type of flat dish or in a three D. Environment that has like fake exercise regular matrix in it. And they also have to be maintained at certain temperature that body temperature. And with certain gas exchanges you don't really think about it. We breathe in oxygen and Excel. Um carbon dioxide. Well the cells need those gasses. So whenever you're growing these cells in a laboratory you have to facilitate that um that gas process. But it's all worth it. All the care that they take is entirely worth it because um this provides this you know single cell population to work with which makes doing experiments much easier. And it's so convenient. You know you don't need 100 million individuals. You just need 100 million cells and that can be grown in a single dish and you can have so much more than that grown in a dish and it's so easy to do. So it's really convenient. But one of the confusing things about it is that research done using cell culture is called different things, depending on who you talk to. So the majority of people called cell culture in vitro research because this means that it's not happening in a living organism and we're not dealing with a rat, we're not dealing with this, we're not dealing with human. So this is in vitro because it's happening essentially in a plastic dish. But if you talk to some people, especially biochemists who like to do things in tubes, biochemists typically tell this in vivo because cells are living. So the experiments you do with cells are in living cells. So they call it in vivo now, which one should you call it? I mean I can give you my preference, my preferences in vitro, but you should probably ask your professor or go with what your book does because um you don't want to miss a question or something just because of this, a misunderstanding swimming back out of the way. So typically when you grow cells and culture, you grow them in some kind of dishes like these. And you can see this red stuff here is the media. So that's providing the nutrients to the cells which are growing on this very bottom plastic layer of this dish. Now, if you're to zoom in what the cells would look like. Is this now? These have been staying with something that makes their nucleus blue, so they wouldn't normally look blue. But if you look at the rest of the cells, so this outside part here, outside of the blue, this is what sells really look like. When you look at them under a microscope, they're transparent. You can see some structures. But I mean, unless you really know what you're looking for, you're not going to know what these are. Um but this is what sells look like and scientists use these cultures to study a lot of different cellular processes. So with that, let's now move on.