Our unwavering commitment to quality and craftsmanship in our products means using only 100% real human material exclusively in our serum, urine, and whole blood controls. UTAK controls are guaranteed to closely and consistently mimic patients? specimens. Our controls are accurately manufactured to the true desired level, not to a modified accepted mean. UTAK 100% human matrices yield predictable, consistent results. ?Human based? matrices do not always behave like all-human materials, which can cause erratic results.