Determination of optimal volume
Different volumes (30, 40, 50, and 100 μL) of serum samples were left
for approximately 24 hours at room temperature to air dry. Tubes with
30, 40, and 50 μL were well dried having a yellowish pellet stuck to the
bottom of the tubes. Tubes with 100 μL were not completely dried. Thus,
50 μL volume of bovine serum was chosen to produce DTS panels and all
subsequent testing was conducted with the DTS prepared using 50 μl
volume of serum.