When a microalbumin or albumin urinalysis test pad turns blue if there is albumin in urine at a constant pH. Results may vary from a pale green to an aqua blue. Normal urine albumin levels are less than 20 mg/L.3 A low level (less than 10 m g/L) will turn the ALB pad white. A result of 20 200 mg/L may signal microalbuminuria. This may suggest early stage kidney disease Results of > 200 mg/L indicate clinical albuminuria. These levels may predict albumin excretion rates of 30 300 mg/24 hrs and >300 mg/24 hrs, respectively.⁴ Exercise, acute illness and fever, and urinary tract infections may raise urine albumin for a time.

Creatinine is a byproduct of creatinine, primarily used in muscle metabolism. Typically, creatinine is filtered from the body by the kidneys. Creatinine in urine results in a color change from orange through green to blue. A normal urine creatinine level is 10-300 mg/dL. Abnormal low levels of creatinine can indicate kidney disease or other underlying symptoms.

A normal urine albumin to creatinine ratio is less than 30 mg albumin/g creatinine. 30-300 mg/g (abnormal) shows microalbuminuria. Higher than 300 mg/g (high abnormal) shows clinical albuminuria.⁵

This test is based on azo-coupling reaction of bilirubin with diazotized dichloroaniline in a strongly acidic medium. Varying bilirubin levels will produce a pinkish-tan color proportional to its concentration in urine. In normal urine, no bilirubin is detectable by even the most sensitive methods. Even trace amounts of bilirubin require further investigation. Atypical results (colors different from the negative or positive color blocks shown on the color chart) may indicate that bilirubin-derived bile pigments are present in the urine specimen and are possibly masking the bilirubin reaction.

This test is based on the peroxidase-like activity of hemoglobin which catalyzes the reaction of diisopropylbenzene dihydroperoxide and 3,3’,5,5’-tetramethylbenzidine. The resulting color ranges from light orange to dark green. The significance of a trace results, or a 5 – 10 non-hemolyzed result, varies among patients, and clinical judgment is required for these specimens on an individual basis. Small amounts of blood with a strip result of 1+ hemolyzed, or a 50 Ery/μL non-hemolyzed result, within 60 seconds are sufficiently abnormal to request a further investigation. Blood is often, but not invariably, found in the urine of menstruating females.

This test is based on the enzymatic reaction that occurs between glucose oxidase, peroxidase and chromogen. Glucose is first oxidized to produce gluconic acid and hydrogen peroxide in the presence of glucose oxidase. The hydrogen peroxide reacts with potassium iodide chromogen in the presence of peroxidase. The extent to which the chromogen is oxidized determines the color which is produced, ranging from green to brown. Glucose should not be detected in normal urine. Small amounts of glucose may be excreted by the kidney.⁶ Glucose concentrations as low as 100 mg/dL may be considered abnormal if results are consistent.

This test is based on ketones reacting with nitroprusside and acetoacetic acid to produce a color change ranging from light pink for negative results to a darker pink or purple color for positive results. Ketones are normally not present in urine. Detectable ketone levels may occur in urine during physiological stress conditions such as fasting, pregnancy and frequent strenuous exercise.^7-9 In starvation diets, or in other abnormal carbohydrate metabolism situations, ketones appear in the urine in excessively high concentration before serum ketones are elevated.¹⁰

This test is based on a double indicator system which gives a broad range of colors covering the entire urinary pH range. Colors range from orange to yellow and green to blue. The expected range for normal urine specimens from newborns is pH 5-7.¹² The expected range for other normal urine specimens is pH 4.5-8, with an average result of pH 6.¹²

This reaction is based on the phenomenon known as the “protein error” of pH indicators where an indicator that is highly buffered will change color in the presence of proteins (anions) as the indicator releases hydrogen ions to the protein. At a constant pH, the development of any green color is due to the presence of protein. Colors range from yellow to yellow-green for negative results and green to green-blue for positive results. 1-14 mg/dL of protein may be excreted by a normal kidney.¹³ A color equal to or greater than 30mg/dL indicates significant proteinuria. Clinical judgment is required to evaluate the significance of trace results.

This test is based on a modified Ehrlich reaction between p-diethylaminobenzaldehyde and urobilinogen in strongly acidic medium to produce a pink color. Urobilinogen is one of the major compounds produced in heme synthesis and is a normal substance in urine. The expected range for normal urine with this test is 0.2-1.0 mg/dL (3.5-17 µmol/L).¹¹ A result of 2.0 mg/dL (35 µmol/L) may be of clinical significance, and the patient specimen should be further evaluated.

This test depends upon the conversion of nitrate to nitrite by the action of gram-negative bacteria in the urine. In an acidic medium, nitrite in the urine reacts with p-arsanilic acid to form a diazonium compound. The diazonium compound in turn couples with 1 N-(1-naphthyl) ethylenediamine to produce a pink color. Nitrite is not detectable in normal urine.⁹ The nitrite area will be positive in some cases of infection, depending on how long the urine specimens were retained in the bladder prior to collection. Retrieval of positive cases with the nitrite test ranges from as low as 40% in cases where little bladder incubation occurred, to as high as approximately 80% in cases where bladder incubation took place for at least 4 hours.

This test reveals the presence of granulocyte esterases. The esterases cleave a derivatized pyrazole amino acid ester to liberate derivatized hydroxy pyrazole. This pyrazole then reacts with a diazonium salt to produce a beige-pink to purple color. Normal urine specimens generally yield negative results. Trace results may be of questionable clinical significance. When trace results occur, it is recommended to retest using a fresh specimen from the same patient. Repeated trace and positive results are of clinical significance.

A urine analyzer is a device that automatically examines urine test strips. It uses reflectance photometry to interpret the colour changes on the strip and provides a quantitative or semi-qualitative result.

The Rapid Response U121S Urine Analyzer is an efficient and accurate tool for interpreting Rapid Response Urinalysis Reagent Strips results. With the ability to read, store, and print results in under two minutes, the U121S Urine Analyzer improves workflow efficiency while reducing the chance of human error.

Yes, urinalysis can detect white blood cells or nitrites, which are indicative of UTIs.