Why does it look like the tubes are at angle in the photo for the Horizontal Centrifuge?

When I look at the tubes in a picture and in the video of the Horizontal PRF Centrifuge, it appears that the tubes are at angle, but this is supposed to be a horizontal centrifuge. Can you explain why this is?

A horizontal centrifuge is more appropriately known as a “swing out” centrifuge. In every horizontal centrifuge, the tubes at rest are at an angle. It is only when the centrifuge is spinning at high speed that the tubes “swing-out” and are horizontal. It is impossible to really see this, because at high RPM you can’t even really see the tubes moving. This is why you don’t see the horizontal photo online and only see the “at rest” picture.

However, you can easily notice on the horizontal centrifuge that the tubes are not fixed to anything and can be moved when you place your hand near the rotor. This ability to move is what causes the “swing out” at high speeds. This is very different than a fixed angle centrifuge, where the tubes are fixed at an angle, cannot be moved, and will not move at high RPM.

The image below might provide some additional help in understanding the difference above. Notice arrow on the horizontal centrifuge (swinging bucket) on the right, indicating the swing out.

We just wanted to add to this topic, a short update, because someone pointed out to us that the picture of the BioPRF centrifuge online shows the tubes at a horizontal position in the online photograph of the centrifuge at rest. Of course, the reason for this is simply that this is just a marketing picture in order to convey the fact that the BioPRF is a horizontal centrifuge. However, in reality the BioPRF tubes are also at an ANGLE when they are at rest. They only swing out to a perfectly horizontal position when the machine reaches a high speed RPM. To reiterate, a horizontal centrifuge is actually what is known as a swing-out centrifuge. This means that the tubes are at angle (or straight) when at rest and ONLY swing out horizontally when the machine reaches a certain RPM.

Of course, the reason why tubes can never be horizontal at rest, is based on basic centrifugation principles. It would be impossible to centrifuge anything properly if tubes were actually horizontal at rest, as the contents of the tubes based on simple gravitational laws would get pushed to the top before any centrifugation. This is why this is NOT how horizontal centrifugation works. The tubes are at an angle at rest and then swing out horizontally upon high speed RPM.