SOP-CM-002 — Routine Urinalysis (Physical Examination, Sysmex UC-1000 / MEDITAPE UC-10S Chemical Strip and Visual Backup, and Microscopic Sediment Examination) SOP

1.0 Purpose

This SOP sets out the standardized three-phase procedure for routine urinalysis at Tarangnan Community Hospital. The phases are macroscopic physical evaluation; automated chemical reflectance examination using the Sysmex UC-1000 analyzer with Sysmex MEDITAPE UC-10S reagent strips, with an approved manual visual backup procedure; and standardized microscopic sediment examination.

2.0 Scope

This procedure applies to all urine specimens submitted for routine urinalysis in the Clinical Microscopy Section of Tarangnan Community Hospital. It covers physical examination, automated reflectance photometry, manual visual strip backup during instrument downtime, standardized centrifugation, microscopic sediment quantification, chemical-microscopic correlation, and diagnostic reporting.

3.0 Definitions

• Reflectance Photometry: An optical measurement technique measuring the intensity of light reflected from reagent strip pads at specific wavelengths, comparing it with calibration standards to quantify color change.
• Sysmex MEDITAPE UC-10S: A 10-parameter urine test strip containing dry reagent test pads for Urobilinogen, Blood, Protein, Glucose, Ketones, Bilirubin, Nitrite, Specific Gravity, Leukocytes, and pH, plus a blank compensation pad.
• Sysmex UC-CONTROL: Commercial two-level assayed liquid quality control material (UC-CONTROL-L Low and UC-CONTROL-H High) used to verify analyzer optical sensors and strip lot performance.
• Sediment Concentration Factor: The volumetric ratio of original uncentrifuged urine to resuspended concentrated sediment (such as 12 mL concentrated to 1.0 mL yields a 12:1 concentration factor).
• Casts: Cylindrical structures formed in the lumens of the distal convoluted tubules and collecting ducts of the kidney, composed of a Tamm-Horsfall (uromodulin) mucoprotein matrix with entrapped cellular or granular debris.
• Downtime Manual Backup: The approved fallback procedure using visual color block comparison against the strip container label when the automated analyzer is inoperative.

4.0 Responsibility

4.1 Hospital Director

• Approves this analytical SOP.
• Ensures ongoing procurement of Sysmex MEDITAPE UC-10S test strips, Sysmex UC-CONTROL materials, and preventive maintenance service.

4.2 Pathologist

• Gives clinical consultation on abnormal sediment findings, atypical casts, dysmorphic erythrocytes, and neoplastic epithelial cells.
• Authorizes and reviews urinalysis reports with significant clinical-pathological discrepancies.

4.3 Chief Medical Technologist / Laboratory Quality Manager

• Maintains and controls this SOP, ensuring all Medical Technologists receive documented training and annual competency evaluation.
• Verifies daily Sysmex UC-1000 calibration, daily UC-CONTROL charts, and analyzer preventive maintenance logs.
• Investigates quality control shifts, optical sensor errors, and test strip lot-to-lot variations per Quality Control Policy.

4.4 Medical Technologists

• Check specimen volume, label integrity, and collection time against the acceptance criteria before starting the examination.
• Perform daily two-level quality control on the Sysmex UC-1000 analyzer and log values in the electronic QC log under Quality Control Policy (registered under F-QM-002-B-V0).
• Execute physical examination, automated chemical strip testing, standardized sediment centrifugation, and microscopic quantification.
• Switch to manual visual strip reading backup during analyzer maintenance or downtime, documenting backup mode on worksheets.
• Correlate chemical and microscopic findings, resolve analytical discrepancies, and authorize final results in the LIS.

4.5 Laboratory Aides

• Clean and disinfect analyzer exterior panels, centrifuge buckets, and microscope workstations daily.
• Empty liquid biohazard waste and replace yellow infectious waste bags according to hospital biosafety guidelines.
• Stock clean centrifuge tubes, glass slides, coverslips, lens paper, and transfer pipettes at the urinalysis workstation.
• Do not dip reagent strips, operate analyzer measuring cycles, read microscopes, or encode urinalysis results.

5.0 Policy / Procedure

5.1 Analytical Principle and Parameter Overview

` Routine Urinalysis Three-Phase Workflow | +---> Phase 1: Macroscopic / Physical Examination | Assess Color (straw to tea-colored) | Assess Clarity / Transparency (clear to turbid) against white/black print | +---> Phase 2A: Automated Chemical Examination (Sysmex UC-1000) | Sysmex MEDITAPE UC-10S 10-parameter test strip | Multi-wavelength reflectance reading (plus blank compensation pad) | Verified by daily Sysmex UC-CONTROL-L & H | +---> Phase 2B: Manual Visual Reading Backup (when analyzer down / maintenance) | Dip <= 1 sec, blot edge, start calibrated digital timer | Read at 60 sec (chemistry) and 60-120 sec (leukocytes) against bottle chart | +---> Phase 3: Standardized Microscopic Sediment Examination 10-12 mL urine centrifuged at 400 x g (1500-2000 rpm) for 5 minutes Decant leaving 0.5-1.0 mL sediment; flick to resuspend; 1 drop (20 µL) 10 LPF scan (casts, epithelial cells) + 10 HPF count (RBC, WBC, bacteria) * Chemical-to-Microscopic Correlation Check before result release `

Routine urinalysis includes three integrated analytical phases:

• Physical Examination: Visual inspection of urine color and transparency against standardized criteria.
• Chemical Examination: Semi-quantitative determination of ten urinary chemical constituents using dry chemistry reagent pads reacting via enzymatic, diazo coupling, or dye-binding reactions. The automated Sysmex UC-1000 uses multi-wavelength reflectance spectrophotometry to measure pad color changes and subtracts intrinsic urine pigmentation via a blank compensation pad.
• Microscopic Sediment Examination: Identification and enumeration of insoluble formed elements (erythrocytes, leukocytes, renal tubular epithelial cells, casts, crystals, bacteria, yeast, and parasites) concentrated by standardized centrifugation.

The ten parameters measured by Sysmex MEDITAPE UC-10S test strips are:

• Urobilinogen: Azo coupling reaction with diazonium salt producing red-violet color.
• Blood (Occult Blood): Pseudoperoxidase activity of hemoglobin and myoglobin catalyzing organic peroxide oxidation of chromogen to green-blue. Intact RBCs produce speckled green dots.
• Protein: Tetrabromphenol blue dye-binding reaction changes from yellow to blue-green in the presence of albumin at constant buffered pH 3.0.
• Glucose: Glucose oxidase-peroxidase double sequential enzymatic reaction generating a green-to-blue chromogen oxidation.
• Ketones: Legal reaction where acetoacetic acid reacts with sodium nitroprusside in an alkaline medium producing a purple complex.
• Bilirubin: Azo coupling of conjugated bilirubin with diazonium salt in an acid medium forming an azo dye.
• Nitrite: Griess reaction where bacterial reduction of dietary nitrate forms a diazonium compound coupling to produce a pink azo dye.
• Specific Gravity (SG): Chelation of polyvalent electrolytes altering pKa of a polyelectrolyte and changing bromothymol blue indicator color from blue-green to yellow-green.
• Leukocytes (Leukocyte Esterase): Granulocytic esterase cleaves an indoxyl ester; released indoxyl couples with diazonium salt to form a violet complex.
• pH: Dual indicator system (methyl red and bromothymol blue) covering pH range 5.0 to 9.0 from orange to blue.
• Blank Pad: Uncoated paper pad reflecting background urine pigment, automatically subtracted by the Sysmex UC-1000 photometer.

5.2 Phase 1: Macroscopic and Physical Examination

• Mix the uncentrifuged urine thoroughly by gentle inversion five times. Do not shake vigorously to avoid persistent froth.
• Pour 10 to 12 mL into a clean, clear, conical centrifuge tube.
• Evaluate Color in a well-lit work area against a white background: - Straw / Pale Yellow (normal, dilute urine) - Yellow (normal, concentrated urine) - Dark Yellow / Amber (highly concentrated, dehydration, or presence of bilirubin) - Red / Pink / Reddish-Brown (gross hematuria, hemoglobinuria, myoglobinuria, or beet ingestion) - Brown / Tea-Colored / Smoky (oxidized blood, myoglobin, or severe bilirubinuria)
• Evaluate Transparency / Clarity by viewing printed black text through the tube against a white card: - Clear (no visible cloudiness; print read easily) - Slightly Cloudy / Hazy (slight turbidity; print readable through tube) - Cloudy (definite turbidity; print partially obscured) - Turbid (thick precipitate; print cannot be seen through tube)
• Record physical appearance immediately on the bench worksheet or LIS.

5.3 Phase 2A: Automated Chemical Examination (Sysmex UC-1000)

5.3.1 Daily Analyzer Setup and Quality Control

• Turn on the Sysmex UC-1000 analyzer. Ensure self-diagnostic initialization passes with no optical or mechanical transport errors.
• Inspect the strip transport tray; clean the calibration white reference pad with a lint-free swab moistened with distilled water if prompted or soiled.
• Quality Control Run: - Allow vials of Sysmex UC-CONTROL-L (Low/Normal) and Sysmex UC-CONTROL-H (High/Abnormal) to stand at room temperature (18 to 25 °C) for 15 minutes. - Invert vials gently five times. - Dip a fresh Sysmex MEDITAPE UC-10S strip into the Level 1 control for no more than 1 second, blot edge, place on the tray, and initiate reading. - Repeat with Level 2 control. - Verify that all ten parameters fall within published target ranges. If any parameter fails, follow corrective action protocol before processing patient specimens.

5.3.2 Patient Specimen Examination Sequence

• Ensure uncentrifuged urine is well mixed and at room temperature (18 to 25 °C).
• Remove one Sysmex MEDITAPE UC-10S strip from the container and recap the bottle immediately. The desiccant in the stopper protects remaining strips from ambient moisture.
• Inspect strip pads: verify that pads are intact, unexposed, and free from discoloration.
• Immerse all reagent pads completely into the uncentrifuged urine specimen for no more than 1 second.
• Remove strip smoothly, dragging the long edge against the rim of the tube to shed bulk urine.
• Touch the long edge of the test strip gently against clean absorbent gauze or filter paper to draw off remaining excess urine. This step prevents chemical cross-contamination between adjacent test pads (especially acid buffer running from protein onto the pH pad).
• Place the strip flat onto the moving sample tray of the Sysmex UC-1000 with reagent pads facing upward.
• The analyzer automatically advances the strip, detects pad positions, measures multi-wavelength reflectance at programmed incubation intervals, subtracts the blank pad reflectance, and displays/prints the analytical report.

5.4 Phase 2B: Manual Visual Reading Backup Procedure (Analyzer Downtime)

When the Sysmex UC-1000 is unavailable due to scheduled maintenance, optical error, or power interruption, activate the manual visual reading procedure:

• Log analyzer downtime status in the Section Downtime Register (F-QM-IT-002-A-V0).
• Verify ambient work area lighting: perform visual reading under bright, indirect daylight or a calibrated white LED bench lamp (avoid direct colored lights or shadows).
• Dip the Sysmex MEDITAPE UC-10S strip into the well-mixed uncentrifuged urine for no more than 1 second and blot the long edge on absorbent paper identically to the automated method.
• Start a calibrated digital stopwatch immediately upon removing the strip from the urine.
• Hold the strip horizontally close to the color blocks on the MEDITAPE UC-10S container label. Do not allow test pads to touch the label surface.
• Read each parameter at its exact manufacturer incubation window: - At 60 seconds: read Glucose, Bilirubin, Ketones, Specific Gravity, Blood, pH, Protein, Urobilinogen, and Nitrite. - Between 60 and 120 seconds: read Leukocyte Esterase (color continues developing up to 120 seconds). - Ignore any color changes occurring after 2 minutes (120 seconds), as progressive oxidation and drying produce invalid false-positive reactions.
• Record semi-quantitative results on the bench worksheet, appending the notation "Visual Reading Mode."

5.5 Phase 3: Standardized Microscopic Sediment Examination

` Standardized Sediment Preparation | +---> 10 to 12 mL well-mixed urine in conical tube | +---> Centrifuge: 400 x g (1500 to 2000 rpm) for exactly 5 minutes | Allow to stop by gentle coasting (NO manual braking) | +---> Decant: Smoothly invert tube; discard supernatant leaving 0.5 to 1.0 mL | +---> Resuspend: Flick tube bottom gently to disperse sediment pellicle | +---> Mount: Pipette 1 drop (~20 µL) onto clean slide; apply 22 x 22 mm coverslip | Prevent air bubbles and liquid overflow | +---> Scan 10 Low-Power Fields (10x LPF) for Casts & Epithelial Cells | +---> Count 10 High-Power Fields (40x HPF) for RBC, WBC, Bacteria, Crystals `

5.5.1 Centrifugation and Sediment Concentration

• Pour exactly 10 to 12 mL of well-mixed uncentrifuged urine into a standardized 15 mL conical graduated centrifuge tube. (If pediatric volume is limited, record exact starting volume, such as 3 mL, to calculate adjusted sediment density).
• Balance centrifuge buckets with opposing counterbalanced tubes.
• Centrifuge at 400 × g (approximately 1500 to 2000 rpm) for exactly 5 minutes.
• Allow the centrifuge to coast to a complete stop without applying mechanical hand braking, which creates turbulence and resuspends concentrated sediment.
• Invert the tube smoothly in a single motion to discard the supernatant fluid. Return the tube upright; the volume of concentrated sediment and residual liquid remaining at the bottom shall measure exactly 0.5 to 1.0 mL.
• Tap or flick the conical tip of the tube gently with a finger to resuspend the sediment pellicle into a homogeneous suspension. Do not aspirate aggressively with pipettes to avoid shear destruction of fragile cellular casts.

5.5.2 Slide Preparation

• Using a disposable transfer pipette, transfer exactly one drop (approximately 20 µL) of the resuspended sediment onto the center of a clean, grease-free glass slide labeled with two patient identifiers.
• Grasp a clean 22 × 22 mm glass coverslip by its edges. Rest one edge at a 45° angle on the slide adjacent to the drop, then lower the coverslip gently over the suspension, allowing surface tension to spread the liquid evenly without trapping air bubbles.
• The liquid suspension shall fill the entire area under the coverslip without overflowing into the surrounding slide or floating the coverslip. Discard and remount if air bubbles or fluid excess are present.

5.5.3 Microscopic Scanning and Enumeration Protocol

• Place the slide on the microscope stage. Lower the condenser slightly and adjust the iris diaphragm to provide subdued contrast illumination (necessary to visualize transparent hyaline casts and mucous threads).
• Low-Power Objective (10× LPF Scan): - Scan at least 10 representative low-power fields across the coverslip, including outer edges where casts tend to migrate. - Enumerate and identify Casts: - Hyaline casts (smooth, transparent, rounded ends; reported as average count per LPF, e.g., 0–2 / LPF). - Granular casts (fine or coarse granules; reported as average count per LPF). - Cellular casts (Erythrocyte casts, Leukocyte casts, Renal Tubular Epithelial casts; critical indicators of renal parenchymal disease requiring Pathologist verification). - Waxy casts (dense, highly refractile with squared ends and cracked fissures; indicate advanced chronic kidney disease). - Broad casts (formed in dilated collecting ducts; represent severe renal failure). - Evaluate Squamous Epithelial Cells: large, flat polygonal cells with small central nuclei; reported semi-quantitatively as Few, Moderate, or Many / LPF (indicates clean-catch quality). - Evaluate Transitional Epithelial Cells: pear-shaped or spherical with central nuclei, originating from renal pelvis, ureters, or bladder. - Evaluate Renal Tubular Epithelial (RTE) Cells: small round cells with prominent eccentric nucleus; presence of > 2 RTE cells / HPF indicates tubular necrosis or injury. - Screen for Mucus Threads and Parasites: Trichomonas vaginalis (flagellated protozoan exhibiting jerky, undulating motility) and Schistosoma haematobium (terminal-spined ova).
• High-Power Objective (40× HPF Detailed Count): - Switch to 40× objective and increase illumination slightly while continuously adjusting fine focus. - Count and average at least 10 representative high-power fields: - Erythrocytes (RBCs): Non-nucleated biconcave discs (~7 µm); report average number per HPF (e.g., 0–2, 2–5, 10–20, > 100 / HPF). Note crenated RBCs in hypertonic urine, ghost swollen cells in dilute urine, or dysmorphic acanthocytes in glomerular disease. - Leukocytes (WBCs / Pus Cells): Spherical cells (~12 µm) with granular cytoplasm and lobed nuclei; report average count per HPF (e.g., 0–5, 10–20, 20–50, Packed / HPF). Note presence of WBC clumps indicating acute pyelonephritis or lower urinary tract infection. - Bacteria: Small rods or cocci displaying brownian movement or motility; reported semi-quantitatively as None, Few, Moderate, or Many / HPF. - Yeast Cells: Oval, refractile budding cells and pseudohyphae (Candida species); distinguish from RBCs by acetic acid insolubility and budding structures. - Crystals: Categorized according to urinary pH: - Acidic Urine: Calcium oxalate (colorless envelope or dumbbell shapes), Uric acid (pleomorphic rhomboids, rosettes, or barrels), Amorphous urates (pink/brick-dust precipitate). - Alkaline Urine: Triple phosphate / struvite (colorless "coffin-lid" prisms), Calcium phosphate (flat plates or prisms), Ammonium biurate ("thorny apple" brown spheres), Amorphous phosphates (white amorphous precipitate). - Abnormal / Pathological Crystals (Acid/Neutral pH): Cystine (clear hexagonal plates), Tyrosine (fine dark needles in sheaves), Leucine (yellow-brown spheres with radial striations), Cholesterol (clear rectangular plates with notched corners), Bilirubin (yellow-brown clusters of needles), Sulfonamide crystals (sheaves of wheat or fans). All abnormal crystals require Pathologist review.

5.6 Chemical-to-Microscopic Correlation and Discrepancy Resolution Table

The examining Medical Technologist shall cross-reference chemical dipstick findings against microscopic sediment elements before authorizing reports:

5.7 Result Reporting Format and Units

Results are compiled into the official TCH Urinalysis Report:

• Physical: Color (straw, pale yellow, yellow, dark yellow, amber, red, brown); Transparency (clear, slightly cloudy, cloudy, turbid).
• Chemical: - Glucose (Negative, Trace, 1+, 2+, 3+, 4+ or mg/dL equivalent) - Bilirubin (Negative, 1+, 2+, 3+) - Ketones (Negative, Trace, 1+, 2+, 3+) - Specific Gravity (1.000 to 1.030, reported to three decimal places) - Blood (Negative, Trace, 1+, 2+, 3+ / Non-hemolyzed vs. Hemolyzed) - pH (5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0) - Protein (Negative, Trace, 1+, 2+, 3+, 4+ or mg/dL equivalent) - Urobilinogen (Normal [0.1–1.0 mg/dL], 2, 4, 8 mg/dL) - Nitrite (Negative, Positive) - Leukocytes (Negative, Trace, 1+, 2+, 3+ / ca. 25, 75, 500 Leu/µL)
• Microscopic: - RBCs: Range per HPF (e.g., 0–2, 2–5, 10–20 / HPF) - WBCs: Range per HPF (e.g., 0–5, 5–10, 20–30 / HPF) - Epithelial Cells: Squamous (Few, Moderate, Many / LPF); Renal Tubular (> 2 / HPF flagged) - Casts: Type and average number per LPF (e.g., Hyaline 0–2 / LPF; Granular 1–3 / LPF) - Bacteria: None, Few, Moderate, Many / HPF - Crystals: Identified type and semi-quantitative rating (Few, Moderate, Many / HPF) - Others: Yeast, Mucus threads, Trichomonas vaginalis

6.0 Records

7.0 References

• DOH Clinical Laboratory QMS Tool, Section 3 — Service Delivery
• DOH Administrative Order No. 2021-0037, Annex B1 — Technical Standards for Clinical Laboratories
• ISO 15189:2022, Section 7.3 — Examination processes
• CLSI GP16-A3, Urinalysis — Approved Guideline
• Sysmex UC-1000 Automated Urine Chemistry Analyzer Operator's Manual
• Sysmex MEDITAPE UC-10S Reagent Strips Product Insert (current lot in use)
• Sysmex UC-CONTROL Product Insert (Level 1 Low and Level 2 High, current lot in use)

Companion policies:

• Scope of Service and Laboratory User Information Policy — Diagnostic test menu and urinalysis scope of service
• Quality Control Policy — Laboratory internal quality control rules and out-of-control investigation
• Laboratory Reporting Policy — Result validation, review, and diagnostic report release