Methods and apparatus for collecting and treating blood component. An
apparatus and methods for improvement of an extracorporeal photopheresis
treatment is described. A cassette having flexible tubes inside its
housing and on the bottom surface outside the cassette housing for ease
of manufacturing is operated with a centrifuge bowl having an inlet and
two outlets, pressure domes for measuring pressures in tubes, an improved
irradiation plate, and a dual chamber bag in an extracorporeal
photopheresis treatment.