Abstract: An apparatus for testing body fluid or blood electrolytes in a body fluid or blood serum sample includes three testing stations. The blood sample is automatically transported from an input point serially and in a linear manner along a track past the three testing stations to an output point. The first testing station removes a first portion of the sample at a first location along the track and has a rotating structure including a container which receives and stores the first portion and rotates it to a first testing position at a first time. A testing structure tests the first portion while at the first testing position at that first time.The second testing station removes a second portion of the sample at a second location along the track and includes a second rotating structure including a container which receives and stores the second portion and rotates the stored second portion to a second testing position, also at the first time.