SAMPLE CASSETTE FOR COLLECTING TISSUE SAMPLES FROM A FLUID STREAM, THE CASSETTE INCLUDING PLURAL CATCH TRAYS FOR RETAINING PLURAL SAMPLES

A cassette for collecting tissue samples from a fluid stream comprises a body with a suction line receiving fitting and an outlet opening. The body comprises a tray-receiving void being in a fluid path with the outlet opening, and a bypass conduit around the tray-receiving void. A catch tray is removably mounted in the tray-receiving void for retaining material above a certain size that is entrained in the fluid flow through the catch tray. A valve is moveably mounted to the body to direct the fluid flow from the fitting into either the bypass conduit or the tray-receiving void. A lock feature is connected to and configured to be moved with the valve to (i) block removal of the catch tray from the tray-receiving void when the valve directs the fluid flow into the tray-receiving void, and (ii) be spaced from the tray-receiving void so as to allow removal of the catch tray from the tray-receiving void when the valve directs the fluid flow into the bypass conduit. A stop is positionable to (i) allow a suction to be drawn on the tray-receiving void through the outlet opening when the valve directs the fluid flow into the tray-receiving void, and (ii) block suction draw on the tray-receiving void from the outlet opening when the valve directs the fluid flow into the bypass conduit.