all right let's get our learn on in this video I want to talk about the electron microscopes so looking at small things it's really cool no doubt about it at least if you like geeking out in the same ways that I do light microscopes are gay great being able to see things at a thousand of the 2500 X is great and we can see bacteria animal cells and tissues really really clearly but if you really want to see small structures if you really want to see cool things I think you need to look at the electron microscopes so I haven't won the lottery yet if I ever do the first thing I'll buy will be a scanning electron microscope I'll tell you I like those better than the transmission electron microscopes myself but so we're looking at you know so the the when I think of the microscope I think of being able to see things in the micrometer range that millionth of a meter range and being able to see you know some things that are in the nanometer range the billions of a meter but the electron microscope is really where we can get really good resolution and really good magnification and see things I mean the actual resolution of a transmission electron micrograph is in the pico meters the trillions of trillions of a meter so all right this is an actual transmission electron microscope they obviously look different than anything you've probably worked with because they are different as you can see here's a nice comparison the light microscope uses lenses to bend and focus light rays to magnify the image well there aren't lenses in electron microscope so we'll look at the transmission electron microscope the TEM versus the scanning electron microscope the SEM in just a moment this is a nice comparison of a light microscope to an electron microscope so they actually since they don't have lenses how do we focus and bend the beam of electrons like we bend light rays with with with the lens well it's actually magnets so electric coils that create electromagnetism are actually what Bend and focus beams of electrons so that's what that's what allows you to get the magnification you do with an electron microscope now here is a comparison of the two and they are quite a bit different this is also why they serve different purposes so on the left-hand side here we see the transmission electron microscope and it truly is a beam of electrons that are traveling through the electron microscope and it those that beam of electrons has actually what creates the image that you can see now the good news with this is that you can get unbelievable resolution unbelievable magnification so the resolution of a transmission electron microscope would be somewhere in the neighborhood of 10 picometers and hopefully recall from earlier videos that what that means is as long as two things are 10 Pico meters or more apart you can tell they're two separate things that's pretty unbelievable and the magnification of a transmission electron microscope can reach a hundred thousand times so versus or more really versus the light microscope which usually is going to get you a thousand x now there's a con here and we can come back to that but there the one major weakness of the transmission electron microscope but on the right hand side we have the scanning electron microscope and you know you hopefully will notice a difference here the scanning electron microscope has a secondary electron detector so what actually happens is you send a barrage of electrons at your sample and it's not electrons passing through them that actually create your image it's the secondary electrons that are bouncing off of them and actually being collected that creates your image so quite a bit different the scanning electron microscope has a resolution much more closer to 10 nanometers instead of ten picometers so you can't get the resolution which is why you can't get the magnification so generally speaking the scanning electron microscope is going to get you at ten or twenty thousand times magnification still amazing whereas the electric transmission electron microscope is going to get you more so here we actually see that the the images are quite different because of those differences so on the left hand side here we see the transmission electron micrograph or a TEM if you have you're looking in a textbook or online and you see TEM it's the transmission electron micrograph well it can see structures that are much smaller and it can see internal structures whereas on the right-hand side we have a colorized scanning elect micrograph they can't see anywhere near the same magnification but they can see the surface structures of a microorganism in three dimensions and that's actually why I'm a bigger fan of the scanning electron microscope than the transmission electron microscope because if you watch my video series on prokaryote anatomy and and the anatomy of a bacteria most of what's amazing about them is on the outside the capsule the sex pilis the the flagella and the flagellar motor the I mean just all sorts of cool things fimbriae so a lot of what's going on in bacteria is happening on their surface if you look on the inside they're basically this kind of back you know cell gut cytoplasm cytosol some ribosomes and a pile of DNA whereas our cells are much more compartmentalised and much more complex on the inside so I think looking at the outside of a bacteria is where it's at and I feel the same way about viruses and stuff as well but so personally I like the scanning electron micrographs scanning electron microscopes better but they both serve unbelievable purposes so here we actually see the biggest weakness with the transmission electron microscope is that if you're going to be passing beams of electrons through a specimen it better be very thin no way they could be more than I'd say 150 nanometers about the ideal so this is called an ike ultra microtome and it's used to usually using a diamond knife to cut ultra thin specimens of an organism there is a way to do it when it's frozen that I think works better but when you cut these all Pathan's specimens they should be in the ballpark of 30 to 60 nanometers so imagine taking a red blood cell and slicing it into 80 to 120 slices that's how thin we're talking so the biggest weakness with the transmission electron micrograph or microscope is that it has to work with ultra thin specimens the scanning electron microscope I was looking at the surface doesn't matter near as much so here just just to review let's compare and contrast the tube so they're both electron microscopes they both use beams of electrons instead of visible light those beams of electrons have really short way link's which gives electron microscopes really good resolution so I'll write them down here again ballpark transmission electron microscope is going to have a resolution of 10 Pico meters whereas the scanning electron microscope is going to have a resolution of 10 nanometers and that's I mean quite a that's a logarithmic difference so I you know a nanometer is a billionth of a meter whereas a Pico meters a trillionth of a meter so since transmission electron microscopes have such a better resolution that is what gives them better magnification so generally when I think of a transmission electron microscope I think of in the ballpark of a hundred thousand times magnification whereas a scanning electron microscope somewhere between ten and twenty thousand times magnification transmission electron microscope sees internal structures here actually looking at the Ebola virus whereas the scanning electron microscope because it uses those secondary electrons is looking at the surface so here we see a really really neat three-dimensional view of the outside of a bacteria are right these this is where we get the images for these videos so thank you for your time I hope these videos are helping you I want you to be inspired by the amazing world we live in I want you to be empowered by what you're learning every day and I want you to be engaged in trying to make this world a better place I really really mean that have a wonderful day you