Abstract: A "micro" hollow fiber bioreactor and method of use are provided for use in screening different cell lines and process conditions. The bioreactor includes the use of an oxygen permeable (e.g., silicone rubber) tube sealably containing a hollow fiber bundle, in order to create an extracapillary space to provide a medium reservoir and an intracapillary space for the growth of cells. The bioreactor avoids the need for oxygen or medium pumps or supply systems, and permits multiple cell lines, and/or multiple conditions to be evaluated simultaneously. Preferably, the tube has an oxygen permeability of between about 100.times.10.sup.-10 to about 10,000.times.10.sup.-10 (cc-mm/sec-cm.sup.2 -cm Hg), the extracapillary space provides a medium reservoir of about 1 ml to about 100 ml, the intracapillary space provides a cell culture volume of about 0.1 ml to about 1 ml, the hollow fibers have a molecular weight cut off from about 1 kD to about 1,000 kD and a pore size of from about 0.

Abstract: A compact, easily assembled cell culturing device comprising at least one cell culturing envelope, the interior of which defines a cell culturing space. The cell culturing envelope is retained within a pair of rigid plates having various reliefs which, in turn, form cavities when the plates are placed together. The cell culturing envelope includes a plurality of hollow fibers disposed in the culturing space formed between upper and lower membrane sheets which are sealed together. Tubes communicate with the culturing space. Accordingly, greater amounts of oxygen are provided to the cells at a faster rate to produce cells and/or cell products more economically and in higher yield.