in this video, we're going to begin our lesson on light microscopes that detect fluorescents. And so in certain situations, light microscopes that detect fluorescents or emitted light can be really useful and so fluorescent can be more formally defined as the ability to absorb short wavelengths of light and then immediately give off longer wavelengths of visible light. Now fluorescent molecules will stand out as bright objects against a darker background. And there are several different types of microscopes that can detect fluorescents. And we'll be able to talk about some of those microscopes as we move forward in our course. And so if we take a look at our image down below at our map of the lesson of on light microscopy, what you'll notice is that great. Out over here on the left, we have the things that we already covered, including bright field microscopes like microscopes that increase contrast, including dark field microscopes, phase contrast microscopes and D. I. C. Microscopes. And so here in this video, what we're focusing on are the light microscopes that detect fluorescence, which moving forward, We're going to be talking about the con focal scanning laser microscope or the C. S. L. Microscope, The two photon microscopes as well as the super resolution microscopes. And so once again we'll be able to talk about each of these different types of microscopes moving forward in our course. But for now this year concludes our brief introduction to light microscopes that detect fluorescence. So I'll see you all in our next video.

in this video, we're going to begin our lesson on fluorescence microscopes. And so fluorescence microscopes are light microscopes that project ultraviolet light onto the specimen, causing the specimen to fluoresce or to emit some form of visible light that can be detected. Now, fluorescence microscopy is able to create these awesome images that are very vibrant and very colorful. Now some organisms have the ability to fluoresce naturally without any modification by the scientist. However, scientists can also tag very specific molecules inside or outside of cells with fluorescent dyes, also known as floor chrome's. And so by tagging these very specific molecules with dies, it allows these molecules to fluoresce when they otherwise would not fluoresce. Now, a very specific technique known as immuno fluorescence is a technique that combines a flora chrome or a fluorescent dye with an antibody, which is a protein that will bind to very specific molecules to tag those specific objects and allow those objects to fluoresce. And so this allows scientists to even track just one specific type of molecule inside of a cell. And so notice down below, we're showing you some images of fluorescence microscopy, which again is able to create these really colorful and vibrant images. Uh So over here on the far left, what we have is uh fluorescent microscopy of human neurons. Where you can see uh these uh specific molecules are being tagged with yellow and purple and red fluorescent dyes. Here we have caenorhabditis elegance being tagged with some kind of molecule that flores. Is this blue color? Uh Then here in the middle what we have is yersinia pestis bacteria, which is the plague bacteria that causes plague. And over here on the far right what we have is Escherichia coli bacteria and these two different strains of this E. Coli being tagged with these different fluorescent dyes. And so this year concludes our brief introduction to fluorescence microscopy. But as we move forward in our course, will be able to continue to learn more and apply these concepts, so I'll see you all in our next video.

in this video, we're going to continue to talk about light microscopes that detect fluorescence by talking about con focal scanning laser microscopes or C. S. L. M. S. And so these con focal scanning laser microscopes, or CSL Ems are computer controlled microscopes that couple a laser to a fluorescent microscope. Now the laser portion is responsible for generating high contrast three dimensional or 3D images. That allows the viewer to access several different planes of focus inside of the specimen. And so this can be used to look inside of cells at different layers of the cell. And so if we take a look at our image down below, we can get a better understanding of these com focal scanning laser microscopes. And so over here on the left, notice that we're showing you that this is a complex device that is going to be controlled by a computer and it links a laser to a fluorescence microscopes. And once again these are abbreviate SCS L. M. S. For calm focal scanning laser microscope. Now, over here on the left on the right, we're showing you some of the images that can be created. And once again this is looking at different planes or different levels of the specimen. And so over here on the left, we're showing you this felon panky ramos, a seed coat. This is showing you arabidopsis italiana cells. And here it's showing you rat pancreas cells. And so this is another form of being able to detect fluorescents using these c s l M s. And so once again, we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.

in this video, we're going to briefly introduce two photon microscopes, or T. P. M. S. And so two photon microscopes, or T. P. M. S, are similar to con focal scanning laser microscopes, or CS LMS. Except the two photon microscopes, as their name implies, is going to be using two photons and less damaging light than the con focal scanning laser microscopes. Now, two photon microscopy is also known as multi photon microscopy at times. And so those are referring to the same thing. And once again, the two photon microscopes, or multi photon microscopes are going to be using longer, less damaging light wavelengths that allow for deeper imaging of really, really thick uh structures. And it also allows for a really cool feature of time lapse imaging, which can create somewhat of a video type of effect. And so if we take a look at this image down below, we can see that the functions of the two photon microscope, uh and the two photon microscope is also abbreviated as just TPM. And it allows for deep imaging somewhat similar to X ray vision you can think of and so notice here, it's showing you mouse brain blood vessels and neurons which is a relative can be thick structures. And it's able to do this deep imaging into those thicker structures and create these really cool looking images. And another feature is that it's able to create these time lapse images. And the time lapse imaging once again allows for somewhat of a video type of effect. And so here it's showing you on the right hand side, uh the mouse brain blood vessels. And it's showing you that the black dots and lines show the red blood cell movement through the actual blood vessels. And so ultimately, the two photon microscopes can be used for deep imaging of thick structures and also to create time lapse images. And so this year concludes our brief introduction to two photon microscope, and we'll be able to apply some of these concepts as we move forward, so I'll see you all in our next video.

in this video, we're going to continue to talk about light microscopes that detect fluorescence by briefly introducing super resolution microscopes or S. R. M. S. And so what's important to note is that up until 2014, when the super resolution microscopes were first the maximum resolution for light microscopes. Before 2014 was only about 0.2 micrometers, which means that objects had to be at least 0.2 micrometers apart from one another in order to distinguish them as separate objects. Now, 0.2 micrometers might seem like a pretty good resolution. However, in comparison to super resolution microscopes, really, 0.2 micrometers is nothing. And this is because super resolution microscopes or S. R. M. S, are fluorescent light microscopes with very high resolution of about 0.1 micro meters, which means that two objects could be 0.1 micro meters apart and you can still distinguish them as being separate objects. And so this 0.01 micrometer resolution is about 20 times greater or 20 times better resolution. In comparison to the other light microscopes. Now, the super resolution microscopes or the srm they use very complex mechanisms in order to visualize molecules that would otherwise be way too close together to be seen as distinct objects. And sometimes these super resolution microscopes can allow for even a single molecule To be tracked within the cell and that is how great of a resolution these super resolution microscopes can provide allowing us to see a lot more detail more clearly. And so if we take a look at our image down below, we can clear up some of these ideas. And so notice on the left hand side of our image, we're focused on the normal resolution fluorescent microscopy that would have existed before 2014 before the super resolution microscope was developed. And so notice that here we are essentially comparing the normal resolution fluorescent microscopy to an old television set maybe from the eighties or nineties. And so this old television set is not going to provide as much detail. And so notice that our cartoon character here saying, what am I looking at? It's kind of difficult to see. The image is a little blurry, Not so great of a resolution. And so notice if we look at the bovine endothelial cell on the left hand side, our bovine endothelial cell looks a little bit blurry. And so the image is somewhat blurry, like what you would expect from an old television set. Now on the right hand side of our image, we're showing you the super resolution fluorescence microscopy which we're comparing to uh flat screen HD tv. That's high quality and has great amaze resolution. And so the image is gonna come out much much more crisp, much more clear. And so notice our cartoon character is saying, oh now I can see and the bovine endothelial cell that's visualized using the super resolution microscope is going to show a lot more detail, a lot more clarity and a lot higher and better resolution. And so this year concludes our brief introduction to super resolution microscopes, or Srm, and we'll be able to get some practice applying these concepts and learn more as we move forward, so I'll see you all in our next video.