Blue Cross Biostix
Professional urine reagent test strips for the rapid determination of Ketones, Glucose, Protein and pH, Leukocytes, Nitrites, Ketones, Bilirubin, Blood, Urobilinogen, and Specific Gravity levels in urine. These are the diagnostic reagent strips used by physicians, clinics and hospitals to initially screen for suspected and/or existing health conditions. Simple to use, urine diagnostic reagent strips can provide early indications of developing health problems and identify potential abnormal functions requiring more extensive testing. Additionally, routine use is frequently recommended by physicians for monitoring certain existing and chronic health conditions.
Blue Cross Biostix 4SG
- Specific Gravity
Blue Cross Biostix 5P
- Ketone (Acetoacetic Acid)
Blue Cross Biostix 10L
- Specific Gravity
Reagent Area Information
GLUCOSE: The test is specific for glucose; no substance excreted in urine other than glucose is known to give a positive result. In dilute urines containing less than 0.28 mmol/L glucose may produce a color change that can be interpreted as positive. Ascorbic acid concentrations of 2.84 mmol/L or greater and/or high Ketone concentrations (4 mmol/L) may cause false negatives for specimens containing small amount of glucose (4-7 mmol/L). The reactivity of the glucose test decreases as the specific gravity of the urine increases. Reactivity may also vary with temperature. The kidney may normally excrete small amounts of glucose. These amounts are usually below the sensitivity of this test but on occasion may produce a color between the ‘Negative’ and the 5.5 mmol/L colou blocks and that is interpreted by the instrument as positive.
BILIRUBIN: Normally no bilirubin is detectable in urine by even the most sensitive methods. Even trace amounts of bilirubin are sufficiently abnormal and require further investigation. Typical colors may indicate bile pigment abnormalities and the urine specimen should be tested further. Metabolites of drugs which give a color at low pH, such as Pyridium and Lodine (etodolac) may cause false positives, or a typical reaction in case of Lodine. Indican (indoxyl sulfate) can produce a yellow-orange to red color response, which may interfere with the interpretation of a negative or a positive bilirubin reading. Ascorbic acid concentrations of 1.42 mmol/L or greater may cause false negatives.
KETONES: The tests react with acetoacetic acid in urine. It does not react with acetone or B-hydroxybutyric acid. Some high specific gravity / low pH urine may give reactions up to and including trace. Normal urine specimens usually yield negative results with this reagent. False positive results (trace or less) may occur with highly pigmented urine specimens or those containing large amounts or levodopa metabolites.
SPECIFIC GRAVITY: The specific gravity tests permit determination of urine specific gravity between 1.000 and 1.030. In general, it correlates with 0.005 with values obtained with the refractive index method. For increased accuracy, 0.005 may be added to readings from urines with pH equal to or greater than 6.5. Strips read instrumentally are automatically adjusted for pH by the instrument. The Biostix test is not affected by certain non-ionic urine constituents such as glucose nor by the presence of radiopaque dye. Highly buffered alkaline urines may cause low readings relative to other methods. Elevated specific gravity readings may be obtained in the presence of moderate quantities (1-7.5 g/L) of protein.
BLOOD: The significance of the ‘trace’ reaction may vary among patients, and clinical judgment is required for assessment per individual case. Development of green spots (intact erythrocytes) or green color (free hemoglobin/myoglobin) on the reagent area within 60 seconds indicates the need for further investigation. Blood is often found in the urine of menstruating females. This test is highly sensitive to hemoglobin thus complements the microscopic examination. The sensitivity of this test may be reduced in urines with high specific gravity. The test is highly sensitive to hemoglobin and thus complements the microscopic examination (Hemoglobin concentration of 150-620 µg/L is approximately equivalent to 5-15 intact red blood cells per microlitre). Microbial peroxidase associated with urinary tract infection may cause a false positive reaction. Levels of ascorbic acid normally found in urine do not interfere with this test.
pH: The pH test area measures pH values generally to within 1 unit in the range of 5-8.0 visually and 5-9 instrumentally.
PROTEIN: The reagent area is more sensitive to albumin than to globulin, hemoglobin, Bence-Jones Protein and mucoprotein; a ‘Negative’ result does not rule out the presence of these other proteins. Normally no protein is detectable in urine by conventional methods, although a minute amount is excreted by the normal kidney. A color matching any block greater than ‘Trace’ indicates significant proteinuria. For urine of high specific gravity, the test area may not closely match the ‘Trace’ color block even though only normal concentrations of protein are present. Clinical judgment is needed to evaluate the significance of ‘Trace’ results. False positive results may be obtained with highly buffered or alkaline urines.
UROBILINOGEN: This test area will detect urobilinogen in concentrations as low as 3 µmol/L (approximately 0.2 Ehrlich unit/dL) in urine. The normal range with this test is 3-16 µmol/L. A result of 33 µmol/L represents the transition from normal to abnormal, and the patient and/or urine specimen should be evaluated further. The reagent area may react with substances known to interfere with Ehrlich’s reagent, such as P-aminosalicylic acid and sulphonamides. A typical color reactions may be obtained in the presence of high concentration of paminobenzoic acid. False negative results may be obtained if formalin is present. Highly colored substances, such as azo dyes and riboflavin may mask color development on the reagent area. Strip reactivity increases with temperature; the optimum temperature is 22o – 26oC. The absence of urobilinogen cannot be determined with this test.
NITRITE: This test depends upon the conversion of nitrate (derive from the diet) to nitrite by the action of principally gram negative bacteria in the urine. The test is specific for nitrite and will not react with any other substance normally excreted in the urine. Pink spots or pink edges should not be interpreted as positive result. Any degree of uniform pink color development should be interpreted as a positive nitrite test suggesting the presence of 105 or more organisms per mL, but color development is not proportional to the number of bacteria present. A negative result does not itself prove that there is no significant bacteria. Negative result may occur when urinary tract infections are caused by organisms which do not contain reductase are present and bladder incubation is ample. Sensitivity of the nitrite test is reduced for urines with high specific gravity.
LEUKOCYTES: Normal urine specimens that generally yield negative results; positive results (+ or greater) are clinically significant. Individually observed ‘Trace’ results may be of questionable clinical significance; however ‘Trace’ results observed repeatedly may be clinically significant. ‘Positive’ results may occasionally be found with random specimens from females due to contamination of the specimen by vaginal discharge. Elevated glucose concentration (160 mmol/L) or high specific gravity may cause decreased test results. The presence of cephalexin, Lodine, cephalothin or high concentrations of oxalic acid may also cause decreased test results. Tetracycline may cause decreased reactivity, and high levels of the drug may cause a false negative reaction.
SPECIFIC PERFORMANCE CHARACTERISTICS: Specific performance characteristics are based on cloinical and analytical studes. In clinical specimens, the sensitivity depends upon several factors: the variability of color perception, the presence or absence of inhibitory factors typically found in urine, specific gravity, pH, and the lighting conditions when the product is read visually. Each color block or instrumental display value represents a range of values. Because of specimen and reading variability, specimens with analyte concentrations that fall between nominal levels may give results at either level. Results at levels greater than the second positive levle for the protein, glucose, ketone, and urobilinogen tests will usually be within one level of the true concentration. Exact agreement between visual results and instrumental results might not be found because of the inherent variability of clinical urines, lesser concentrations may be detected under certain conditions.
- Biostix (4sg) 4 Parameters
- Biostix (5P) 5 Parameters
- Biostix (10L) 10 Parameters