If you desire 4oC during your spin cycle, you must allow the machine to cool to that point before it will allow you to press start.
If you use too small of a volume (< half full) in the ultracentrifuge tubes, they will collapse!
Tubes with only 1/2 mL liquid collapse in ultracentrifuge.
It is hard to say how much is enough, but it seems to be about 1 mL. 1/2 mL definitely collapsed on Janet in 5/2013.
We should be able to find smaller-volume tubes for our rotor. (link)
You probably won't be able to get any sample out of a collapsed tube.
When they collapse it is very tricky to get them out. Needle nose pliers are probably your best bet but it can still be very hard.
If the ultracentrifuge won't start and won't even try to start, open the door, lift the rotor up, place it back down, let it cool back down to your desired temp, and hold start.
Example Protocols
To spin down the membranes and membrane-bound proteins in a crude extract, centrifuge for 45,000 RPM at 4oC for 1 hour. With our MLS-50 mushroom-shaped rotor, this is 163,000xg at raverage (108,000xg at rminimum).
Important Info about Rotor & Tubes
Tubes should never be less than half filled or they will collapse. - Tech support 5/2013 via Janet
This is true for every tube material and size.
You can wash and re-use tubes, however, deformed tubes will collapse.
Be careful to wash them with compatible liquids. See the manuals.
There are seals inside the swinging buckets (tube holders) that seal the sample when you screw the bucket lid tight. These are very important. The ultracentrifuge uses a strong vacuum to keep the samples chilled. If the seal fails, your sample will be sucked out of the swinging basket and end up in the vacuum. There is no way to recover after this.
Tech support said we should replace them yearly and have spares on hand. I am skeptical, as this doesnt factor in how heavily the system is used.
Parts & Info
A fuller product spec sheet for the MLS-50: MLS-50 product sheet from website PDF
