Abstract: Portable apparatus for repeatedly taking samples of blood or other body fluid from a person or animal comprises a housing adapted to be attached to the person or animal from which the samples are to be taken. The housing contains a pump having an inlet connected to a catheter inserted in the body of the person or animal and an outlet connected through a conduit and a multiple position first control valve to a storage receptacle having provision for separately storing a plurality of individual samples. A reservoir for rinsing fluid is connected through a second control valve to the conduit just downstream of the pump. A control system comprising a radio receiver for remote control controls the pump and second control valve to admit body fluid and rinsing fluid alternately to the conduit and controls the first control valve to direct individual samples of body fluid to the storage receptacle and to discharge rinsing fluid from the conduit.