Patent ID: 6070476
Filing Date: 2000-06-06
Classification: F04B,G01N

Abstract:
A method of testing cell properties of a cellular sample using a fluid delivery apparatus comprising at least first and second delivery syringes, each delivery syringe comprising a syringe housing defining a tubular passage having a fluid outlet, and a syringe plunger arranged to slide axially within the tubular passage and seal one end of the tubular passage, the fluid delivery apparatus further comprising syringe plunger drive means for driving the syringe plunger of the first and second syringe along at least part of the length of the respective tubular passage according to a predetermined velocity profile for the delivery syringe and discharging fluid through the fluid outlet, the method comprising the steps of:a) premixing the cellular sample with a first dilutent to form a fluid source and supplying the first delivery syringe with the fluid source;b) supplying the second delivery syringe with another fluid source; andc) sliding the plungers within the syringes with the drive means according to the predetermined velocity profile of each delivery syringe so that a combined flow rate of fluid discharged simultaneously from the outlets of the delivery syringes is maintained substantially constant over at least a portion of the range of movement of the plurality of plungers.