 So, in thinking about centrifuges, we have, just when our department, at least 10 different centrifuges with several different types of rotors, probably for each centrifuge. And so I'm going to be showing you some of these centrifuges and some of their rotors and adapters and whatnot to give you an idea of the different features that will be available. Like I said, this is no way a comprehensive presentation of, you know, all the different kinds of centrifuges and whatnot. But here, as you're just learning the basics of the operation of centrifuges, I think it's good just that you even learn the nomenclature and what we call the parts and basically how they work. This first centrifuge, you see here that the CL2 centrifuge is a classification that we call clinical centrifuge, and it's a tabletop clinical centrifuge because you can see it sitting here on the tables, opposed to a floor model centrifuge. And so it's fairly small, lightweight, so it's somewhat portable. It's called clinical because this would be the type of centrifuge that would be possibly used in a lab that's processing blood, and so it has features designed for that. You could also use it in a lab that's doing cell culture because cells are fairly dense and don't require excessively high speeds to bring them down, and in fact, spinning them too hard can actually cause the cells to rupture and kill the cells. So it's important that we know the speed required for what we're spinning. So you can see it's fairly simple in that it has a speed control and a time, and that's kind of the bases of controlling the centrifuge anyway. It has how long it's going to spin, and the speed that it's going to turn. We have a start button and a stop that also opens the lid. In our program, we principally use this clinical tabletop centrifuge for cell culture and you can see I have it fitted here with two types of carriers, one for the 15-mil centrifuge tube and one that would hold the 50-mil centrifuge tubes. You can also see by standard practice that the 15-mil carriers are placed opposite each other and the 50-mil carriers are placed opposite each other. It's very important in centrifuge operation that you consistently have the rotors balanced, so you would not want to place different sized tubes or different types of carriers opposite each other because the 15-mil carriers are meant to be balanced with 15-mil tubes and the 50-mil tubes carriers should be matched also. This as you can see is a swinging bucket rotor so that these swing, they have the removable buckets or tube carriers that fit into these rings. We call these rings trunnion rings and so this is, like I say, this is a typical centrifuge for handling cells. Here's a small mini-fuge, a mini-centrifuge or we sometimes call them micro-centrifuge tubes because they're set up to spin these micro-centrifuge tubes. We sometimes refer to this small type here as a personal centrifuge. We might call them that because in a molecular biotechnology lab they're used frequently. Just when we're pipetting a lot of small volumes of materials into these tubes, we give them quick spins to bring the liquids down, make sure that they mix and combine in the tube. We may actually pipet them onto the sides of the tube and use this mini-fuge to bring them down and they're fairly inexpensive so that each technician could have their own centrifuge so that it doesn't slow down your process. Like I say, they're used a lot in molecular biotechnology. This rotor here is interchangeable with this strip tube rotor that you can actually spin strips of PCR tubes in there. So this is kind of a specialty adapter for labs that do a fair number of procedures with these small PCR type tubes. Here we have another micro-centrifuge. This one calls itself the mini-spin. It also is for spinning the micro-centrifuge tubes. The major difference in this one and the kind of personal centrifuge is this one spins at a much higher rate of speed. This particular centrifuge will go to a speed of 14,500 rpm. So it's a little bit heavier. We have our time and speed control and so we can open it and we see the rotor inside that in this case is a covered rotor which prevents turbulence and inside we see the rotor for the micro-centrifuge. This one we would call a 12-place rotor and it has 12 places to put the tubes. We could place the tubes into the micro-centrifuge and as usual balancing them we would have tubes of equal volumes in opposite places. Here we see them in position 1 and 7. So the holes in this centrifuge rotor are made specifically to handle these 1.5 mils micro-centrifuge tubes. It's also possible to spin these smaller PCR tubes by placing them in these adapters, these adapters which fill up the space so that we can spin the smaller tubes in these carriers and you must always remember with these high-speed micro-centrifuge tubes to replace the cap on it before starting the centrifuge. Here we've got the Centra CL3 which is the big brother of the CL2 that we've already looked at and so this is a larger centrifuge that's still considered a tabletop centrifuge but you see it's larger so it's a larger capacity in that we're going to see that the rotors can carry larger volumes and there are a few more controls on here. We still have a speed control although this one you can either set it for speed or reciprocal centrifugal force. We have time there and this one has rotor recognition so that it recognizes the different types of rotors so that it can actually figure the correlation of speed and g-forces with it. It also has the ability to control the rate of acceleration, how fast it takes to get to its speed and how fast it slows down. If you have a substance that pellets pretty tightly you can afford to be slowed down rapidly but if you have cells or some components that don't pack so tightly and you slow them down too fast it can actually resuspend them by the slowing down braking action of the rotor and then we have the start and the stop and the open. Okay looking inside we can see that it's got a little larger rotor and this again is a four place or four bucket rotor and you can see that the buckets are a little bit larger so we have a higher capacity. Here we see a carrier that we can put in that has two 50 mil tubes. We have carriers that hold multiple smaller test tubes and they're a whole assortment of other types of rotors that can be used in this or carriers that can be used in this rotor in this centrifuge. These carriers can also be fitted with these aerosol containment caps. If you were spinning blood or a hazardous liquid you can use these caps so there's the tube cracks or the lid would crack or something would happen to the tube that contains your liquid in the carrier and doesn't release it into the centrifuge. So all these different size adapters just give the centrifuge a lot of flexibility in the types of tubes and samples you can centrifuge. In fact I'm going to take this rotor out and replace it with this rotor here. That's pretty simple. Now this rotor I'll put its carriers in and so this is what we actually call a microplate rotor and so it can actually spin plates in the microplate format and spin you'd have to have a balance plate that can actually spin those 96 well plates and other plates that have the similar dimensions to bring them down. Now this type of rotor because of its kind of lack of aerodynamics would have a slower, would have a lower maximum speed than other types of rotors but so these are just two rotors for this centrifuge and there are other rotors that are available to give centrifuges like I say a lot of flexibility. Going along with this idea of the flexibility of the lab centrifuge with a variety of rotors and adapters here we have a foot called an air shielded rotor. The typical swinging bucket rotor we like those because the swinging buckets swing horizontally so that our materials are pelleted into the bottom of the tube but they have limitations to their speed that they can spin because they're kind of open and they create a lot of turbulence and friction that causes heat while they're spinning so in order to have the same swinging bucket arrangement and be able to spin them at a higher speed then this type of rotor we call an air shielded rotor you can see that this one says that it has 13,000 rpm maximum which is a lot faster than we get with a standard swinging bucket. You can see that these buckets in fact do swing out to horizontal but they're contained in this heavy shielded outer container and so then we could have our tube inside an adapter then that would fit inside this swinging bucket so there are tubes that would fit into that carrier without adapter this particular size tube is just a little bit smaller and requires this adapter so as usual this rotor comes with a number of adapters for the different types of tube you can get. It's important to have match adapters because when you get to spinning tubes at high speed they really need to be supported so that they don't collapse or be compressed crushed basically by the speed the G forces that are being created so here's another type of rotor in case that we need more G forces than we can get from our swinging bucket rotor we can go to this fixed angle rotor this one has a maximum speed of 22,500 rpm and we can see then that it's basically a big solid hunk of metal with the individual tube places around it in this case so the tube would fit directly into there this is a proper size tube for this rotor so it is supported by the rotor but being a fixed angle rotor the G forces going kind of to this point here will pellet the material on the side of the tube and the lower end rather than in the bottom like I said this is a heavy metal rotor they're now making equivalent rotors in out of carbon fiber which actually can have a longer life and be less expensive than these precisely machined metal rotors because these have to be at the speeds they're turning have to be perfectly balanced here we have just a bucket off of a swinging bucket rotor I didn't bring the whole heavy rotor here but this is one of four buckets that go in the centrifuge and you can see this bucket is specifically made to carry a conical bottom plastic centrifuge bottle and so that the carrier is conical and there's even a conical adapter that is in there so that it's very important with these conical tubes that this adapter supports this cone because with the force on on this tip it could easily compress compress that tube if it weren't supported here's another bucket from that same centrifuge it's just a standard open bucket that would take either a large bottle or wide variety of those adapters and I've just included one particular adapter here just to show you a centrifuge bottle we're not just working with tubes we just saw the conical centrifuge bottle and this is a centrifuge bottle you can see it's made out of a plastic capable of handling at high speed and it has even a gasketed cap so that the actual liquid in any that is in there helps contain it any of these kind of tubes and bottles that you use in a centrifuge you have to be aware of what the manufacturers stated maximum g-forces that it can handle because centrifuge bottles and tubes are made for specific uses and that they're not universal uses so there are materials that can handle a thousand G's but can't handle twelve thousand G's and whatnot so it's important when you're using a centrifuge that you know the specifications on the container that you're using to prevent failure of that container and loss of your sample and an unhappy centrifuge