Abstract: A diagnostic device in the form of a blood glucose monitoring strip of the dip-and-read variety, and which has a first, outer test area which is chemically identical with a second, interior test area. A blood sample is tested in the first area. The first area is torn off and discarded. Then, another, similar test is conducted employing the remaining, second, interior test area. A line of perforation divides the first and second areas. Notches may be defined in the outer ends of both test areas to facilitate reading of the blood impregnated samples with the use of a suitable photometric machine, for example.