The ornamental design for a diagnostic testsystem, as shown and described.
FIG. 1 is a front perspective view of our diagnostic test system.
FIG. 2 is a front perspective view of the design of FIG. 1 with a test strip inserted.
FIG. 3 is a rear perspective view of the design of FIG. 1.
FIG. 4 is a top view of the design of FIG. 1.
FIG. 5 is a rear view of the design of FIG. 1.
FIG. 6 is a left side view of the design of FIG. 1.
FIG. 7 is a front view of the design of FIG. 1; and,
FIG. 8 is a right side view of the design of FIG. 1.
The bottom of our diagnostic test system is not visible during normal use and does not form part of the claimed design. The broken lines in the figures are for illustrative purposes only and do not form part of the claimed invention.