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Flow cytometry charges

PPMS Charging

The flow cytometry facility runs on a full-cost recovery basis. For that reason, we do have to make a charge for use of our instruments. The analysers are charged at £23/hour of use and the cell sorters are charged at £58/hour for users from the University of Cambridge. External users are charged at a different rate. 

Keep in mind that all booked sessions are adjusted with real usage. The real usage is detected because we installed a tracker that connects to the booking system PPMS in all the flow cytometers workstations. The tracker will lock the workstation screen and to unlock it users need to type their PPMS credentials. The tracker will report back to PPMS the user’s activity every minute until the user clicks the logout button that will lock the screen again.


Booked time vs real-time usage

To maximise instrument usage the booked sessions are adjusted with real usage. That means, for example, if you book 3 hours on an analyser, and come 1 hour late you will be charged the full 3 hours even if you only used 2h. And if you book 3 hours and use 4 you will be charged 4 hours. 

We know, however, that experiments not always run according to plan and you might be late to come and use the instrument. For that reason, we allow users to move the session on the same day without penalty. If you know you will be late, log into PPMS, click on your session and cancel it. Then re-book it at an appropriate time. 

Keep in mind that a session is defined by the length of time. For example, a user who booked from 14h to 16h (2 hours) can move it 15h to 17h and will have no penalties. If the user moves it to 15h until 16h, the user will be charged 1h at 50% (unless someone else uses it) because the new session is one hour shorter.

It is also good practice to adjust your booking if you know you will be late because that will free up time on the instruments that one of your colleagues can book.



However, there is a penalty for sessions that are cancelled too late and not rescheduled. On the analysers there is a minimum of 12 hours and on the cell sorters a minimum of 24 hours to cancel a booking without a penalty fee. Late cancellations are charged 50% of the hourly rate.

The reason we created a charging penalty is to make sure users are not making multiple bookings and not using them.