A window assembly includes a window frame defining a frame perimeter and at least one window mounted in the frame. The flapper has a gasket which is sandwiched between a flapper base and a flapper cover. Mounting the electronic components to stand upright off the motherboard allows air to enter below the components and rise up through the passageway producing an increase in air speed and better convective cooling. The invention also relates to the preservation of cells that have been identified after immunuomagnetic selection and fluorescent labeling in order to further interrogate the cells of interest.