Falsely Negative Enzyme Paper Tests for Urinary Glucose

TAPES OR STICKS impregnated with glucose oxidase and peroxidase have achieved widespread use for the detection of glucose in urine. Replacement of the Benedict's test by these enzymatic glucose determinations has occurred in many hospitals and clinics, as well as in medical offices and patients' homes.1The tapes are strips of paper continuously impregnated with glucose oxidase and peroxidase, while the sticks are strips of paper containing a narrow band of similar impregnation. In the following paragraphs, we wish to: (1) call attention to inhibitory substances for enzymes in some urines; (2) point out an advantage of the tape over the stick paper; and (3) suggest certain precautions in the use of these glucose enzyme test papers. It was found in our general hospital laboratory that an occasional urine was positive to the routine Benedict's test but negative to the enzyme dipsticks (Combistix) for glucose. An additional step