Load the rotor, then respond to a break

Two decisions make up this segment. The first is a loading check: given a described rotor, tube set, and opposing positions, decide whether the load is balanced and approved to run. The second is an incident response: given a described tube breakage or suspected rotor spill during or after a run, choose the defensible sequence of actions.

For the loading check, apply the same reasoning used in the guided case to a specific load. A four-position swinging-bucket rotor has top and bottom as one opposing pair and left and right as the other. The top position holds a tube, cap, and adapter assembly with a complete mass of 42 g, and the opposite bottom position holds a matched 42 g assembly; the left and right positions each hold a matched 38 g assembly. Every opposing pair matches complete mass and position, so this load is approved to run. If the bottom position instead held only an empty adapter at 18 g while the top position still held its 42 g assembly, the opposing pair would be mismatched by mass, and the run would not start until the load was corrected.

For the incident response, a broken tube or suspected rotor spill is an aerosol and exposure problem before it is a specimen problem. Keep the lid closed, restrict access, allow the laboratory's defined aerosol-settling interval where one applies, then use assigned personal protective equipment and the local spill and exposure procedure. Sealed rotors and safety cups are primary containment devices that reduce aerosol, droplet, and leakage release; when a risk assessment calls for containment, load and unload them inside a biological safety cabinet or another suitable containment device. Any contaminated surface or equipment gets cleaned and decontaminated with an appropriate disinfectant as soon as feasible, and equipment that cannot be decontaminated before service or shipment must be labeled and communicated as contaminated.

An unresolved loading question or a suspected spill both have the same first move: stop and do not proceed until the uncertainty or contamination is addressed by the local procedure.