Abstract: A hand operated press is used for extracting cell sap from biological tissue, such as from leaf tissue of plants, as well as from animal tissue as a removable barrel that holds a suitable screen in place in a well. The barrel houses a plunger that is of small diameter so that when the barrel has tissue added to it the plunger is inserted and a substantial pressure may be exerted manually to insure rupturing the cell membranes and releasing all of the cell liquid (in plants called sap) for analysis. In the preferred form the screen holds at least one standard size filter paper disk in place so that the liquid is first forced through the screen to retain large solid particles, and the filter paper disk is wetted for use in a standard analyzer for direct analysis of the desired characteristics.