Comparing Slide Systems for Microscopic Urinalysis

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1 CLINICAL MICROSCOPY G. Berry Schumann, MD Sheryl K. Friedman, MT(ASCP) Comparing Slide Systems for Microscopic Urinalysis Recently, two new manual and semiautomated ABSTRACT We evaluated two new, closed, microscopic microscopic urinalysis systems have been introduced to the clinical laboratory. The Cen-Slide slide systems (Cen-Slide [Davstar California, Newport Beach, Calif] and R/S 2000 [DiaSys, Waterbury, Conn]), system (Davstar California, Newport Beach, Calif) is an easy-to-use, safe, closed system that and three open systems (Uri-Slide [Fisherbrand, Pittsburgh, eliminates decanting, pipetting, and coverslipping of the microscopic slide. It consists of a Pa], KOVA [ICL Scientific, Fountain Valley, Calif], and Count-0 [V-Tech, Palm Desert, Calif]). We identified flat-base slide viewing area in an unbreakable physical differences among systems. Both new systems disposable unit. required less time and handling of the sample and fewer The R/S 2000 system (DiaSys, Waterbury, and easier technical steps in loading sediment onto the slide Conn) involves a wraparound workstation that consists of a control unit. This unit contains a than did the open systems. Using low concentrations of erythrocytes and leukocytes, we observed comparable results circuitry, and a closed glass optical slide assembly pump that is a peristalic type, valves, electronic with the R/S 2000, KOVA, and Uri-Slide systems. When we or chamber that eliminates the use of pipettes, examined known urine samples containing mucus, erythrocytes, leukocytes, crystals, bacteria, fungi, casts, and epitheli slides, and coverslips. Both manufacturers report comparable results with these systems and the KOVA (ICL Scientific, Fountain Valley, Calif) um, acceptable routine microscopic urinalysis results were microscopic urinalysis system. produced and confirmed using specialized cytodiagnostic urinalysis. This preliminary study indicates that the R/S 2000 provides an efficient alternative for laboratories that perform the Figure: standardized wet sediment examinations on all urines. From Cytopathology and Cytotechnology, Dianon Systems, Stratford, Conn (Dr Schumann and Ms Friedman), and the University of Connecticut School of Allied Health Professions, Storrs, Conn(Dr Schumann). Reprint requests to Dr Schumann, Director, Cytology, Dianon Systems, 200 Watson Blvd, Stratford, CI In the early 980s, standardized systems were developed for performing routine wet microscopic urinalyses. In 986, we reported that manual slide systems that were commercially available proved to be far superior to the conventional 22X22-mm glass-slide method.- Since then, there has been increasing evidence that the conventional "-drop" method is imprecise and should not be considered a standardized technique. 2 ~ 6 Some investigators called for more comparative analyses to determine the effectiveness of manual or automated systems for standardized wet microscopic urinalysis. In this study, we compared physical features of the following instruments, which are shown in Uri-Slide-Four test slide (Fisherbrand, Pittsburgh, Pa). KOVA 4 slide. Count-0 slide (V-Tech, Palm Desert, Calif), Cen-Slide and Cen-Slide 60 Centrifuge. R/S " 0 We evaluated the distribution of sediment elements with the five systems. We compared cellular counts in samples with low concentrations of erythrocytes (trace-2+ reagent strip reactions) and with low levels of leukocytes (trace-2+ reagent strip reactions). In addition, we compared wet urinalysis results in known sediments containing mucus, bacteria, fungi, casts, crystals, and epithelial cells and fragments and correlated these with confirmatory specialized cytodiagnostic urinalysis. We will discuss the advantages and limitations of these manual and semiautomated open and closed systems. For a guide to LABORATORY MEDICINE VOLUME 27, NUMBER 4 APRIL 996 Downloaded from on 20 February 208

2 terminology commonly used in urinalysis, see "Terms Commonly Used in Urinalysis." (A) LRI-SLDE 4 lirl-slide 0 Material and Methods We reviewed manufacturers' technical information and procedural steps on how to perform a standardized routine microscopic urinalysis. 6-0 Urine specimens and cellular suspensions were collected following processing in the diagnostic urine cytopathology laboratory at Dianon Systems in Stratford, Conn. We prepared low concentrations of erythrocyte suspensions from fresh blood. Known samples of patients with pyuria were used to evaluate low concentrations of leukocytes. Appropriate dilutions were made and adjusted to reagent strip reactions of trace to + and to 2+ using the Chemstrip-0 (Boehringer Mannheim, Indianapolis, Ind). All reagent strip reactions were recorded at the recommended intervals according to manufacturers' instructions. Both authors reviewed physical features of all systems, and the following parameters were assessed: Open vs closed Slides per case and maximum number of cases per slide or plastic coverslip, slide, or both Grids Estimated volume of sediment Viewing surface area Chamber depth Number of microscopic focal planes Slide volumes were reported from manufacturers' information and previously published data. 2 We measured the microscopic surface area and averaged results. Nikon Labophot (Nikon, Melville, NY) microscopes were used to evaluate lowpower fields (LPFs) (X00) and high-power fields (HPFs) (X400). We used hypercellular urine sediments with abundant erythrocytes, leukocytes, and casts to assess the number of focal planes. To determine the precision of each system, we used low concentrations of erythrocytes and leukocytes and a standard preparatory protocol. We poured aliquots of exactly 0 ml of thoroughly mixed suspension into disposable centrifuge tubes, except for the Cen-Slide, which consists of its own centrifuge and viewing tube. Microscopic elements were enumerated by one author (SKF), and results were reviewed and confirmed by the other author (GBS). Brightfield microscopy was used exclusively. The five (B) KOVA SLIDE 4 KOVA SLIDE 0 (C) COUNT-4 COUNT-0 <»> namta. CEN-SLIDE Cen-SWe» Holder microscopic systems were analyzed simultaneously and were tested in the following order:. Uri-Slide.KOVA Count-0 Cen-Slide. R/S 2000 Coefficients of variation (CVs) were determined by performing 0 separate tests for erythrocytes and leukocytes, and the distribution was evaluated by establishing the range of counts over five random HPFs. Number of casts was reported per LPF; an average of five fields was reported. Bacteria, fungal forms, crystals, mucus, and epithelium were graded 0 to 4+ per HPF. Known, in-house urine sediment samples were produced following specialized cytodiagnostic urinalysis testing. Known samples (E) R/S 2000 Commercially available manual and semiautomated slide systems for wet routine microscopic urinalysis. c 3 o 6 i Downloaded from VOLUME 27, NUMBER 4 LABORATORY MEDICINE 27 on 20 February 208

3 with mucus, crystalluria, hematuria, pyuria, bacteruria, funguria, casts, and epithelial cells and fragments were diluted to 3 ml, which allowed ample sediment for simultaneous evaluation of each system. We assessed the sediment distribution and visual clarity of the previously mentioned elements. Wet, unstained microscopic urinalysis findings were reported on four systems and correlated with confirmatory cytodiagnostic urinalysis results that were Papanicolaou-stained. Results Physical Features Sediment Volume and Distribution Physical features and some differences of each slide system are listed in Table. No significant difference in the urine volume between hypocellular and hypercellular urine specimens was noted. Delivery of a monolayer of sediment was controlled best with the R/S The open systems required greater technical skill. Cen-Slide delivery was controlled by centrifugal force and was not amenable to evaluation. In general, initial delivery of sediment was more difficult with the open systems. The R/S 2000 consistently achieved a uniform distribution of sediment. In addition, this system required fewer technical skills owing to an automated loading of sediment or "charging" step. The other systems are manual, require greater technical education and skills, and are subject to variation among personnel. The R/S 2000 required less time for viewing multiple samples. Terms Commonly Used in Urinalysis Bacteruria presence of bacteria in the urine Casts a molded, cylindrical structure that is formed as a result of cellular conglutination and protein precipitation in the lumen of the nephron and extruded into the urinary sediment Crystalluria excretion of crystals in the urine, producing renal irritation Cylindruria presence of tube casts in the urine Dysmorphic having structural defects or fragmentation Erythrocyturia erythrocytes in urine Funguria fungi in the urine Hematuria abnormal presence of blood in urine Isomorphic having the same form Leukocyturia discharge of leukocytes in the urine Microhematuria abnormal bleeding detected by reagent strip or using a microscopic examination Morphology form and structure Microscopic Viewing Surface Features of the microscopic examination surface area and others are summarized in Table. The Uri-Slide had the largest viewing area of the standardized systems (90 mm 2 ). The viewing area for the Cen-Slide was 88 mm 2 and for the R/S 2000, 38 mm 2. The highest numbers of focal planes were observed with the Count-0 and Cen-Slide systems. Monolayer could be achieved with all systems following 30 seconds of settling, reducing the problem of variable cell levels or focal planes. Wet Microscopy Microscopic Clarity Material composition of the slides and coverslips is listed in Table. The Cen-Slide has a tapered and flattened plastic viewing area, and the R/S 2000 has a permanent glass chamber. The R/S 2000 had superior clarity of images owing to the high optical qualities of glass as opposed to plastic. Increased focal planes detracted from the clarity of the Cen-Slide. Erythrocyturia Microscopic urinalysis results of a specimen with low concentrations of erythrocytes are summarized in Table 2. A trace to + and 2+ positive reagent strip reactions for blood correlated with erythrocyte counts per HPR The range, mean value, and CVs are listed in Table 2. The Cen- Slide had the highest CV. In general, all systems easily recognized erythrocyte morphology. Isomorphic red blood cells, including crenated forms, were distinguished readily from dysmorphic types. Leukocyturia Microscopic urinalysis results of urine samples with low concentrations of leukocytes are summarized in Table 3. A trace to + and to 2+ reagent strip reaction for leukocyte esterase correlated with leukocyte counts per HPF. The range, mean value, and CVs are listed in Table 3. The Cen-Slide had the highest CV. Leukocyte morphology was similar in all systems. White blood cells (WBCs) were distinguished from RBCs and urothelial cells. The discrimination of WBCs from renal tubular cells was more difficult with all systems when compared with cytodiagnostic urinalysis. Known Cellular Samples Determination of the presence of sediment elements such as erythrocytes, leukocytes, mucus, 272 LABORATORY MEDICINE VOLUME 27, NUMBER 4 APRIL 996 Downloaded from on 20 February 208

4 TABLE. PHYSICAL FEATURES OF UNSTANDARDIZED CONVENTIONAL AND STANDARDIZED WET ROUTINE URINALYSIS SLIDE SYSTEMS* Parameter Conventional Uri-Slide KOVA Count-0 Cen-Slide R/S2000 System type Open Open Open Open Closed Closed Slide/case Maximum no. of cases/slide 4,0 4,8 0 NA Slide Coverslip Grids available No Yes Yes No No Yes Sediment volume 50 ml 6 ml 6mL 6mL 30 ml 5mL Viewing area (mm 2 ) No. of x00 fields No. of X400 fields 2, No. of focal planes * Uri-Slide (Fisherbrand, Pittsburgh, Pa); KOVA (ICL Scientific, Fountain Valley, Calif); Count-0 (V-Tech, Palm Desert, Calif); Cen-Slide (Davstar California, Newport Beach, Calif); R/S 2000 (DiaSys, Waterbury, Conn). TABLE 2. COMPARISON OF ERYTHROCYTES WITH FIVE WET ROUTINE MICROSCOPIC URINALYSIS SYSTEMS Blood/Hemoglobin Reagent Strip Reaction Trace-+ 2+ Value CV T Value System* Range (Mean) (%) Range (Mean) Uri-Slide KOVA CV (%) Count Cen-Slide R/S * Uri-Slide (Fisherbrand, Pittsburgh, Pa); KOVA (ICL Scientific, Fountain Valley, Calif); Count-0 (V-Tech, Palm Desert, Calif); Cen-Slide (Davstar California, Newport Beach, Calif); R/S 2000 (DiaSys, Waterbury, Conn), t CV indicates coefficient of variation. TABLE 3. COMPARISON OF LEUKOCYTES WITH FIVE WET ROUTINE MICROSCOPIC URINALV SIS SYSTEMS.0 Leukocyte Esterase Reagent Strip Reaction Trace-+ Value CV* 2+ Value CV System* Range (Mean) (%) Range (Mean) (%) Uri-Slide KOVA Count Cen-Slide R/S * Uri-Slide (Fisherbrand, Pittsburgh, Pa); KOVA (ICL Scientific, Fountain Valley, Calif); Count-0 (V-Tech, Pa m Desert, Calif); Cen-Slide (Davstar California, Newport Beach, Calif); R/S 2000 (DiaSys, Waterbury, Conn), t CV indicates coefficient of variation. Downloaded from APRIL 996 VOLUME 27, NUMBER 4 LABORATORY MEDICINE on 20 February 208

5 TABLE 4. COMPARISON OF REAGENT STRIP REACTIONS WITH FOUR WET STANDARDIZED MICROSCOPIC URINALYSIS SYSTEMS AND CONFIRMATORY CYTODIAGNOSTIC URINALYSIS** Case Reagent Strip Reaction Uri-Slide (0 HPFs) KOVA (0 HPFs) Count-0 (0 HPFs) R/S 2000 (0 HPFs) Cytodiagnostic Urinalysis 3+ blood >,000RBCS >,000RBCS >,000 RBCS >,000 RBCS Isomorphic hematuria 3+ esterase >,000WBCs >,000WBCs >,000WBCs >,000WBCs Marked inflammation Mucus Mucus 2 3+ blood 4-6 RBCS 2-4 RBCs 2-4 RBCs Isomorphic hematuria + esterase WBCs WBCs WBCs WBCs Mild inflammation 3+ blood RBCS RBCs RBCs RBCs Isomorphic hematuria Epithelium Epithelium Epithelium Epithelium Benign epithelium 2+ blood 5-8 RBCs 8-0 RBCs 6-8 RBCs 4-8 RBCs Dysmorphic hematuria 2+ protein Crystals Ischemic necrosis 2+ blood 8-2 RBCs; dysmorphic 5-0 RBCs; dysmorphic 4-6 RBCs; dysmorphic 0-5 RBCs; dysmorphic Renal bleeding 2+ protein Mucus + esterase 4-6 WBCs 2-4 WBCs 2-4 WBCs 3-6 WBCs Casts/LPF: 0- hyaline; 0- granular; 0- hyaline; 0- granular 0- hyaline; 0- granular 0- hyaline; Pathologic casts increase morphologic detail. These systems can- not identify epithelial alterations and neoplastic changes, however. Detailed nuclear and cytoplas- mic features are not recognizable using wet microscopy, casts, crystals, bacteria, fungi, and epithelium is summarized in Table 4. None of the systems had a problem with morphologic recognition of common sediment entities. Various sediment elements correlated acceptably with confirmatory cytodiagnostic urinalysis results. Although not required, phase contrast or supravital stain would 274 LABORATORY MEDICINE VOLUME 27, NUMBER 4 APRIL 996 Downloaded from on 20 February 208

6 TABLE 4. COMPARISON OF REAGENT STRIP REACTIONS WITH FOUR WET STANDARDIZED MICROSCOPIC URINALYSIS SYSTEMS AND CONFIRMATORY CYTODIAGNOSTIC URINALYSIS (Cont)* + Case Reagent Strip Reaction Uri-Slide (0 HPFs) KOVA (0 HPFs) Count-0 (0 HPFs) R/S 2000 (0 HPFs) Cytodiagnostic Urinalysis Trace blood 2+ esterase 3+blood 2+ esterase.,...-4.".';. 0 blood 0 blood Trace protein Trace blood 90-05WBCs 2+ fungi 7-8 RBCs WBCs 2-3+ bacteria 2-3 RBCs 5-8 RBCs 6-4 WBCs Squames Atypical urothelium WBCs 2+ fungi 7-5 RBCs WBCs 2-3+ bacteria -2 RBCs 5-0 RBCs 8-8 WBCs Squames ORBCs WBCs 2+ fungi 7-0 RBCs WBCs 2-3+ bacteria 4-6 RBCs 0-5 WBCs Squames 95-5 WBCs 2+ fungi 6-0 RBCs WBCs 2-3+ bacteria 4-8 RBCs 5-0 WBCs Squames Atypical urothelium Fungal UTI Bacterial UTI Reactive urothelium Normal Normal Normal Normal Hematuria Urothelial dysplasia * HPF indicates high-power field; RBC, red blood cell; WBC, white blood cell; UTI, urinary tract infection; P04, phosphates; Ca, calcium. t Uri-Slide (Fisherbrand, Pittsburgh, Pa); KOVA (ICL Scientific, Fountain Valley, Calif); Count-0 (V-Tech, Palm Desert, Calif); R/S 2000 (DiaSys, Waterbury, Conn). WWW Discussion We evaluated two new, closed microscopic The most important consideration in the micro- slide systems for routine wet microscopic urinalyscopic examination of urine sediment is to distin- sis (R/S 2000 and Cen-Slide). Optical clarity of guish the contents of normal sediment from that urine sediment elements was superior with the of abnormal sediment. " 3 To determine R/S 2000 owing to microscopic viewing through whether a specific increase of any one or a num- glass rather than plastic. Because both systems are ber of sediment elements is present and whether closed, they provide increased safety in handling this increase indicates a pathologic condition of the urine sample and eliminate pipetting, slide the urinary tract, sediment examination results charging, and coverslip aligning. More focal must be precise, accurate, and reproducible. 3 planes were noted with the Cen-Slide, and greater Urinoscopists must develop laboratory procedures that promote accurate recognition and diagnosis of disease states. problems existed using high magnifications (X400). The R/S 2000 displayed the urine sediment within a few seconds and had only one to two focal planes. o e o I «V) Downloaded from VOLUME 27, NUMBER 4 LABORATORY MEDICINE on 20 February 208

7 TABLE 5. NORMAL VALUES OF STANDARDIZED WET ROUTINE MICROSCOPIC URINALYSIS FINDINGS SUGGESTED BY THE MANUFACTURERS* System 7 Uri-Slide KOVA Count-0 Cen-Slide R/S 2000 RBCs/HPF I 3-3 WBCs/HPF Sediment Entities Casts/LPF 0-2 hyaline 0-2 hyaline Crystals (Nonpath) 0-3 Bacteria * Each urinalysis laboratory should establish its own normal ranges based on its patient population. RBC indicates red blood cell; HPF, high-power field; WBC, white blood cell; LPF, low-power field. t Uri-Slide (Fisherbrand, Pittsburgh, Pa); KOVA (ICL Scientific, Fountain Valley, Calif); Count-0 (V-Tech, Palm Desert, Calif); Cen-Slide (Davstar California, Newport Beach, Calif); R/S 2000 (DiaSys, Waterbury, Conn). 0-5 Technically, more steps were required to use the open systems. In contrast, the R/S 2000 was easier to operate, required less training, and eliminated technical variance from different individuals preparing the sediment for the slide. In 974, Winkel and colleagues reported that urine microscopy is believed to be imprecise because of variation in technique, sediment volume, interpretation of sediment findings, microscope differences, and time of day. 4 The R/S 2000 solves many of these problems. Hematuria and leukocyturia (pyuria) are important clinical indicators of urinary tract disorders. An assessment of erythrocyturia vs hematuria and pyuria or leukocyturia often is performed in the physician's office and the clinical laboratory. 5 Up to three erythrocytes and up to two WBCs per HPF may be found in normal individuals. Persistent excretion of more than three erythrocytes per HPF indicates further evaluation of the genitourinary tract is necessary. 6 While other researchers have assessed high levels of RBCs and WBCs with these systems, our study sought to determine how the systems would perform at normal or borderline abnormal levels of RBCs and WBCs. When comparing routine urinalysis results using low concentrations of erythrocytes and leukocytes (trace-2+ reagent strip reactions), similar enumerations were produced among systems, except lower values were observed with the Count- 0 system. Comparable results were observed with the R/S 2000 and the KOVA and Uri-Slide systems. The CVs were comparable, except for higher CVs with the Cen-Slide system. We believe these low CVs are due to only 0 tests being performed, low levels being counted and averaged, and the involvement of experienced microscopists. Manufacturers' reference ranges for wet routine microscopic urinalysis are listed in Table 5. The laboratory involved in urine examination must set criteria for the routine, rapid assessment of urine specimens and for more time-consuming specialized testing (ie, cytodiagnostic urinalysis). 7 When examining known urine sediment samples containing mucus, crystals, erythrocytes, leukocytes, bacteria, fungi, casts, and epithelial cells, comparable results were achieved with the R/S 2000 and confirmed with specialized cytodiagnostic urinalysis. We were unable to evaluate the quantitative aspects of the Cen-Slide because of numerous focal planes and poor clarity of plastic. As with all wet urinalysis systems, further characterization of cellular casts, epithelial abnormalities, and inclusion cells was required. We found no major disadvantages with the R/S 2000; we did not, however, evaluate cleaning and maintenance. Specimens containing abundant mucus or fibrin require full purging of the system to prevent cross-contamination. This is not a problem because each purge requires only 6 seconds. A major disadvantage of the Cen-Slide is its lack of adaptability to high-magnification objectives with various microscopes. Reproducibility of results with the other standardized systems requires further evaluation. In the 970s and 980s, clinical laboratories often were selective in deciding which urine specimens required microscopic evaluation. In 979, the usefulness of macroscopic urinalysis as a screening procedure was proposed. A wet microscopic examination was necessary only in those patients for whom routine chemistries were macroscopically positive or in symptomatic individuals with or without known renal or urinary tract disease. 8 Since that time, improvements have been made and the conventional method deplored as a standardized microscopic procedure. 6 An important feature of these two new closed systems 276 LABORATORY MEDICINE VOLUME 27, NUMBER 4 APRIL 996 Downloaded from on 20 February 208

8 is their ability to allow a rapid assessment of the urinary sediment for correlation with clinical and physicochemical findings. As we approach frontline diagnostic urine testing, systems like the R/S 2000 will increase our effectiveness in separating normal and abnormal urine samples. These new systems provide a practical and efficient method for the immediate or rapid assessment of sediment to detect and monitor microhematuria, leukocyturia, urinary tract infections, crystalluria, cylindruria, and epithelial alterations. These systems should be of special interest to the laboratory and physician's office where most urine sediments are evaluated microscopically. References. Ferris JA. Comparison and standardization of the urine microscopic examination. Lab Med. 983;4: Schumann GB, Tebbs RD. Comparison of slides used for standardized routine microscopic urinalysis. / Med Technol. 986;3: Schumann GB, Schweitzer SC. Examination of urine. In: Henry JB, ed. Clinical Diagnosis and Management by Laboratory Methods. 8th ed. Philadelphia, Pa: WB Saunders; 99: Brunzel NA. Fundamentals of Urine and Body Fluid Analysis. Philadelphia, Pa: WB Saunders; 994: Ringruds KM, Linne JJ. Examination of the urine sediment. Urinalysis and Body Fluids. A Colortext and Atlas. St Louis, Mo: Mosby; 995:8-90. URINE MICROSCOPICS CONTROL quantscopics is designed to validate urine processing and centrifugation. Just pour the control into the centrifuge tube and spin. Up to two-year refrigerated stability even after opening Liquid, human urine-based and ready-to-use Human red cells, white cells and crystals URINE DIPSTICK CONTROL the dipper is designed to simulate dipstick testing. Just immerse the dipstick directly into the control. Up to eighteen-month refrigerated stability even after opening Liquid, human urine-based and ready-to-use Assayed for hcg and all ten dipstick analytes Call today for samples 800/ Routine Urinalysis and Collection, Transportation and Preservation of Urine Specimens: Approved Guidelines. Wayne, Pa: National Committee for Clinical Laboratory Standards; 995. NCCLS-GP6-A. 7. Whale Scientific. Technical bulletin. Commerce City, Colo: Whale Scientific; ICL Scientific. Technical bulletin. Fountain Valley, Calif: ICL Scientific; V-Tech Inc. Count-0 Systems. Technical bulletin. Palm Desert, Calif: V-Tech Davstar. The Cen-SUde Systems. Technical bulletin. Newport, Calif: Davstar Schumann GB, Schumann JL, Marcussen N. Cytodiagnostic Urinalysis of Renal and Lower Urinary Tract Disorders. New York, NY: Igaku-Shoin; Addis T. The effect of some physiological variables on the number of casts, red blood cells, white blood cells and epithelial cells in the urine of normal individuals. / Clin Invest. 926;2: Haber MH. A Primer of Microscopic Urinalysis. Fountain Valley, Calif: ICL Scientific; Winkel P, Statland B, Jorgenson K. Urine microscopy, an ill-defined method examined by a multi-factorial technique. ClinChem. 974;20: Shenoy UA. Current assessment of microhematuria and leukocyturia. In: Schumann GB, ed. Clinics in Laboratory Medicine. Philadelphia, Pa: WB Saunders; 985: Tisher CC, Wilcox CS. Nephrology. 3rd ed. Baltimore, Md: Williams and Wilkins; 995:3-5, Schweitzer S, Schumann JL, Schumann GB. The urine sediment examination: a coordinated approach. Lab Management. 983;2: Schumann GB, Greenberg NF. Usefulness of macroscopic urinalysis as a screening procedure. A preliminary report. Am J Clin Pathol. 979;7: \V\^: fe\'? e *. u looking for controlling pair Out of control? Get your personal introduction to this dynamic duo. Our perfect pair will stretch your budget. Quantimetrix believes in Commitment. To our customers a promise of quality Quantimetrix Salutes National Lab Week simple solutions for a complex world 2005 Manhattan Beach Blvd. Redondo Beach, CA For more information circle no. 04 on card Downloaded from VOLUME 27, NUMBER 4 LABORATORY MEDICINE on 20 February 208