A centrifuge is bought as a machine and a rotor together, because the rotor decides the force, the tube format and the kind of separation, and a protocol that names a force in g rather than a speed is the only kind that transfers between laboratories.
centrifuge rotor types and what each is for
centrifuge rotor types are fixed angle, swinging bucket and vertical, and they differ in the path a particle travels: swinging buckets suit gradients and plates while fixed angle rotors pellet fastest. A rotor's maximum speed, its fatigue life and its usage log are what a safety programme tracks, and derating with age is normal rather than exceptional.
A temperature controlled centrifuge, also sold as a cooling centrifuge
A temperature controlled centrifuge and a cooling centrifuge are the same refrigerated machine under two names, which splits a catalogue search. The comparisons that matter are temperature stability under load, the time to pre-cool, and whether the rotor can be stored in the machine, since a cold rotor is what actually keeps a sample cold.
A benchtop centrifuge for 50ml tubes
A benchtop centrifuge for 50ml tubes needs a rotor that takes conical tubes at the force the protocol names, and that combination rather than the machine is what has to be checked, because the largest buckets rarely reach the highest speeds. Adapters let smaller tubes ride in the same rotor and are part of the purchase.
A portable centrifuge and what it cannot do
A portable centrifuge is a small fixed or modest speed instrument for field and point of care separation, and its limit is the force it reaches rather than its capacity, so a protocol citing thousands of g cannot be run on one. Power source and a rotor that holds the tube format used are the practical specifications.
different types of centrifuges and where each belongs
The different types of centrifuges in a laboratory are the microcentrifuge for tubes, the benchtop swinging bucket for plates and conicals, the refrigerated floor model for volume and the ultracentrifuge for subcellular work, and they differ by force and rotor range rather than by brand. A stated force in g is what makes a protocol portable.
A used pcr machine and what to check on any used instrument
A used pcr machine, like any used instrument, is worth buying only if it can still be serviced and verified: block uniformity, lamp or detector condition where fluorescence is read, and whether the control software runs on a supported operating system. A thermal verification with a calibrated probe is the check that decides it.
Questions people ask about cold centrifuge
Speed or force?
Force in g, always. Speed alone cannot transfer between rotors of different radius.
Why store the rotor in the machine?
A pre-cooled rotor is what keeps the sample cold. The chamber alone warms the rotor on the first spin.
What limits a portable instrument?
The force it reaches. Capacity is rarely the constraint; thousands of g is.