A manifold system for biotechnology uses, comprising: a manifold unit which is pre-sterilized and disposable so as to be adapted for single-time usage, including: (a) at least one length of tubing (31, 48) having at least one inlet end portion, at least one outlet end portion, an outside surface, and an inside surface which is sterilized for passage of a biotechnology fluid therethrough, (b) at least one single-use container (21, 22, 23, 44, 54, 58, 61, 62, 63, 81, 82) in fluid communication with said tubing, (c) at least one single-use sensor (102, 155, 158) that senses parameter combinations that include a pH sensing function combined with at least one other sensing function selected from the group consisting of electrical conductivity, oxygen, temperature and combinations thereof, (d) at least one valve (41, 42, 43, 51, 52, 53, 95, 96) remotely operable to engage the length of tubing; (e) a single-use separation component (33, 56, 101) selected from the group consisting of a separation unit, a purification unit, a sterilizing filter and a combination thereof positioned along said length of tubing such that the biotechnology fluid can flow therethrough at a location upstream of said outlet end portion; and a controller arranged for controlling operation of said valve, said controller having control logic which dictates the timing of opening and closing of said remotely operable valve responsive to the parameters sensed at the sensor; wherein: the single-use sensor has usage counter capabilities, comprising an on-sensor memory device and an associated time event feature; and said time event feature is initialized by achievement of a threshold event and is counted as sensor use after having been maintained for a pre-selected time interval, whereupon the counted sensor use is stored on the memory device and accumulates with prior or subsequent uses, as needed until a maximum use total is attained. a manifold unit which is pre-sterilized and disposable so as to be adapted for single-time usage, including: (a) at least one length of tubing (31, 48) having at least one inlet end portion, at least one outlet end portion, an outside surface, and an inside surface which is sterilized for passage of a biotechnology fluid therethrough, (b) at least one single-use container (21, 22, 23, 44, 54, 58, 61, 62, 63, 81, 82) in fluid communication with said tubing, (c) at least one single-use sensor (102, 155, 158) that senses parameter combinations that include a pH sensing function combined with at least one other sensing function selected from the group consisting of electrical conductivity, oxygen, temperature and combinations thereof, (d) at least one valve (41, 42, 43, 51, 52, 53, 95, 96) remotely operable to engage the length of tubing; (e) a single-use separation component (33, 56, 101) selected from the group consisting of a separation unit, a purification unit, a sterilizing filter and a combination thereof positioned along said length of tubing such that the biotechnology fluid can flow therethrough at a location upstream of said outlet end portion; and (a) at least one length of tubing (31, 48) having at least one inlet end portion, at least one outlet end portion, an outside surface, and an inside surface which is sterilized for passage of a biotechnology fluid therethrough, (b) at least one single-use container (21, 22, 23, 44, 54, 58, 61, 62, 63, 81, 82) in fluid communication with said tubing, (c) at least one single-use sensor (102, 155, 158) that senses parameter combinations that include a pH sensing function combined with at least one other sensing function selected from the group consisting of electrical conductivity, oxygen, temperature and combinations thereof, (d) at least one valve (41, 42, 43, 51, 52, 53, 95, 96) remotely operable to engage the length of tubing; (e) a single-use separation component (33, 56, 101) selected from the group consisting of a separation unit, a purification unit, a sterilizing filter and a combination thereof positioned along said length of tubing such that the biotechnology fluid can flow therethrough at a location upstream of said outlet end portion; and a controller arranged for controlling operation of said valve, said controller having control logic which dictates the timing of opening and closing of said remotely operable valve responsive to the parameters sensed at the sensor; wherein: the single-use sensor has usage counter capabilities, comprising an on-sensor memory device and an associated time event feature; and said time event feature is initialized by achievement of a threshold event and is counted as sensor use after having been maintained for a pre-selected time interval, whereupon the counted sensor use is stored on the memory device and accumulates with prior or subsequent uses, as needed until a maximum use total is attained. the single-use sensor has usage counter capabilities, comprising an on-sensor memory device and an associated time event feature; and said time event feature is initialized by achievement of a threshold event and is counted as sensor use after having been maintained for a pre-selected time interval, whereupon the counted sensor use is stored on the memory device and accumulates with prior or subsequent uses, as needed until a maximum use total is attained.