SOP-CM-001 — Clinical Microscopy Section Workflow, Specimen Acceptance, Quality Control, and Result Reporting SOP

1.0 Purpose

This SOP sets out the workflow for the Clinical Microscopy Section at Tarangnan Community Hospital: specimen collection and acceptance, daily internal quality control, correlation of results, and retention of specimens after examination. It covers urinalysis, fecalysis, pregnancy testing, and stool rapid immunoassay examinations, in line with Department of Health regulatory standards and ISO 15189:2022 principles.

2.0 Scope

This procedure applies to all examinations performed in the Clinical Microscopy Section of Tarangnan Community Hospital. Testing activities covered include routine physical, chemical, and microscopic urinalysis; routine fecalysis via direct fecal smear; qualitative urine human chorionic gonadotropin testing; Helicobacter pylori stool antigen rapid testing; and qualitative immunochemical fecal occult blood testing.

3.0 Definitions

• Clinical Microscopy: The diagnostic laboratory section dedicated to the physical, chemical, and microscopic analysis of urine, feces, and other non-blood body fluids.
• Clean-Catch Midstream Urine: A voided urine specimen obtained after thorough periurethral cleansing, discarding the initial stream to flush urethral contaminants, and collecting the middle portion into a sterile container.
• Direct Fecal Smear (DFS): A microscopic wet mount preparation of fresh stool emulsified separately in physiological saline and Lugol's iodine to detect helminth eggs, larvae, protozoan trophozoites, and cysts.
• Internal Quality Control (IQC): An operational mechanism using known control materials to continuously evaluate analytical system performance, reagent integrity, and operator technique before patient specimens are analyzed.
• Result Correlation: A review comparing macroscopic appearance, chemical reagent strip reactions, and microscopic findings to verify clinical consistency before releasing diagnostic reports.
• Critical Specimen: An irreplaceable, time-sensitive, or unrepeatable specimen, such as infant catheterized urine or fresh unpreserved diarrheal stool, requiring immediate handling and priority processing.

4.0 Responsibility

4.1 Hospital Director

• Approves this SOP and ensures budget is provided for the analytical equipment, commercial control materials, and disposable consumables the section requires.
• Supports the laboratory infrastructure and biosafety resources the Clinical Microscopy Section needs.

4.2 Pathologist

• Provides technical and clinical oversight of diagnostic procedures and quality control in Clinical Microscopy.
• Reviews and authorizes complex, atypical, or clinically discordant microscopic findings referred by Medical Technologists.

4.3 Chief Medical Technologist / Laboratory Quality Manager

• Maintains and reviews this SOP, verifies staff competency, and oversees daily quality control records.
• Keeps an inventory of fresh test strips, control materials, and rapid test kits, stored under manufacturer-specified conditions.
• Investigates quality control failures, specimen rejections, and equipment nonconformances per LAB-QM-010.

4.4 Medical Technologists

• Receive, inspect, and verify urine and stool specimens against established labeling and acceptance criteria.
• Perform daily two-level quality control on the automated urine chemistry analyzer and verify internal procedural controls on rapid test cassettes.
• Execute physical, chemical, and microscopic examinations strictly following section operating procedures and safety standards.
• Correlate chemical findings with microscopic sediment elements, perform technical validation, and authorize official reports in the laboratory information system.
• Notify treating clinicians promptly when critical or urgent abnormal results are identified.

4.5 Laboratory Aides

• Receive sealed specimen containers at the laboratory reception window and transfer them to the Clinical Microscopy processing bench.
• Clean and disinfect bench surfaces, centrifuges, and microscope stages at the start and end of each work shift under Medical Technologist direction.
• Record daily temperature logs for laboratory refrigerators and ambient room monitors.
• Maintain stock levels of clean collection containers, centrifuge tubes, microscope slides, and coverslips.
• Package and handle segregated biohazard waste bags and sharps containers according to laboratory biosafety rules.
• Do not perform specimen examinations, interpret microscopic fields, verify test results, or authorize laboratory reports.

5.0 Policy / Procedure

5.1 Routine Clinical Microscopy Workflow

The operational workflow for specimen receipt, stability verification, quality control, analytical examination, and chemical-microscopic correlation follows the standardized sequence (see Figure 1).

Figure 1 — Clinical microscopy specimen stability, QC, and chemical-microscopic correlation flow

• Receive and accession specimen at laboratory reception window, verifying container suitability, label integrity, and requisition details. Assign a laboratory accession number and log the specimen into the daily register.
• Evaluate physical characteristics of the specimen, recording color, clarity, and any gross blood or mucus upon opening the container.
• Perform chemical dipstick and rapid testing by analyzing uncentrifuged urine with reagent test strips or inoculating rapid test cassettes (hCG, H. pylori, FOBT) per method protocols.
• Prepare specimens for microscopic review by standardizing and centrifuging urine to concentrate sediment, or preparing dual saline and Lugol's iodine direct fecal smears.
• Perform microscopic examination using low-power and high-power fields to identify and count cellular components, casts, crystals, bacteria, and parasites.
• Correlate chemical findings with sediment elements, comparing macroscopic, chemical, and microscopic observations to verify consistency before release.
• Encode validated results into LIS and release official report, signed by the examining Medical Technologist.
• Store recapped specimens under refrigeration for the required holding period, complete clinical microscopy examination, and discard waste into designated biohazard containers.

5.2 Urine Specimen Collection, Handling, and Acceptance Criteria

` Urine Specimen Receipt Window | +---> Check Container & Labeling (2 Identifiers, Clean/Sterile Wide-Mouth) | +---> Check Volume: Minimum 12 mL (>= 30 mL Preferred; Infants Documented) | +---> Check Elapsed Time Since Voiding: | +-- <= 2 Hours at Room Temperature -----> ACCEPT for Immediate Examination | +-- > 2 Hours without Refrigeration ----> REJECT & Request Immediate Recollection | +-- Refrigerated at 2 to 8 °C (<= 6 Hours) -> Equilibrate to 18-25 °C & Mix Thoroughly `

5.2.1 Collection Container and Volume Requirements

• Urine specimens shall be collected in clean, dry, leak-proof, wide-mouth plastic containers with secure screw-top lids. Sterile containers are required when microbiological culture referral is anticipated.
• The standard minimum volume for routine urinalysis is 12 mL (30 to 50 mL preferred) to ensure adequate volume for physical inspection, complete dipstick pad immersion, and standardized sediment centrifugation.
• For pediatric and neonatal patients where voided volume is limited, a minimum volume of 3 to 5 mL is accepted. The examining Medical Technologist shall document the limited volume on the bench worksheet and adjust the sediment concentration factor accordingly.
• Pediatric collection bag precautions: When adhesive pediatric bags are used for infants, nursing staff shall cleanse the perineum thoroughly, apply the bag securely, inspect the bag every 15 to 30 minutes, and transfer collected urine immediately to a clean container to avoid cutaneous bacterial contamination and red blood cell lysis.

5.2.2 Specimen Timing and Stability Governance

• First-morning clean-catch midstream urine is strongly preferred for routine urinalysis and pregnancy testing. Concentrated overnight urine provides the highest specific gravity, lowest risk of false-negative chemical reactions, and optimal preservation of cellular elements and casts.
• Random midstream urine is accepted for urgent emergency admissions and routine outpatient clinics when collection occurs after periurethral cleansing.
• Unpreserved urine analyzed within 2 hours of voiding ensures accurate, reliable test results.
• If analysis cannot start within 2 hours, store the specimen refrigerated at 2 to 8 °C for up to 6 hours from collection.
• Bring refrigerated specimens to room temperature (18 to 25 °C) for 15 to 20 minutes and mix thoroughly by gentle inversion before performing chemical dipstick or microscopic analysis. Cold urine inhibits enzymatic reactions on reagent pads (such as glucose oxidase and leukocyte esterase) and causes false-negative readings.

5.2.3 Degradation Mechanisms in Delayed Unpreserved Urine

Urine kept at ambient room temperature beyond 2 hours undergoes rapid physical, chemical, and cellular deterioration:

• Commensal and contaminating bacteria multiply rapidly, consuming urinary glucose and causing false-negative glucose readings.
• Urease-producing bacteria (such as Proteus and Klebsiella) metabolize urea into free ammonia, driving urinary pH above 8.0.
• Erythrocytes, leukocytes, and hyaline or cellular casts lyse rapidly in alkaline, dilute, or hypotonic urine, producing false-negative microscopic counts despite positive chemical dipstick blood or protein reactions.
• Exposure to room light oxidizes bilirubin to biliverdin and urobilinogen to urobilin, resulting in undetectable dipstick levels.
• Temperature shifts cause extensive precipitation of amorphous urates (in acidic urine) or amorphous phosphates (in alkaline urine), obscuring casts and cellular elements during microscopic evaluation.

5.2.4 Urine Specimen Rejection Criteria

Reject specimen and document on Specimen Rejection Form F-QM-PRE-002-A-V0 if any of the following rejection conditions occur, requesting an immediate recollection:

• Specimen container unlabeled, mislabeled, or exhibiting mismatched patient identifiers between container label and laboratory requisition.
• Leaking, cracked, or unsealed collection container presenting biosafety or cross-contamination hazards.
• Visible contamination with feces, toilet paper, vaginal discharge, pubic hair, or topical creams/powders.
• Insufficient volume (< 12 mL for adult routine urinalysis; < 3 mL for pediatric bag collections).
• Unpreserved specimen kept at ambient room temperature for more than 2 hours without verified cold-chain storage.
• Urine collected during active menstrual bleeding, unless specifically requested by the attending physician with clinical indication documented.

5.3 Stool Specimen Collection, Handling, and Acceptance Criteria

5.3.1 Collection Instructions and Contamination Prevention

• Patients shall be instructed to defecate into a clean, dry bedpan, plastic receiver, or clean paper container, and transfer the required aliquot into the specimen container using the collection spoon attached to the cap.
• Do not sample stool directly from toilet bowls because chemical disinfectants neutralize microorganisms and toilet water causes osmotic lysis.
• Stool specimens shall not be contaminated with urine, which rapidly destroys fragile vegetative protozoan trophozoites (Entamoeba histolytica, Giardia lamblia).
• Stool specimens submitted in infant disposable diapers are unacceptable due to fluid absorption and fiber contamination; diaper collection requires lining the diaper with clean plastic wrap to prevent absorption.

5.3.2 Stool Specimen Rejection Criteria

• Stool specimen contaminated with urine, toilet water, soil, or menstrual blood.
• Container contaminated with external fecal matter or lacking a leak-proof screw-cap seal.
• Specimen submitted in absorbent materials, matchboxes, paper towels, or disposable diapers without impermeable plastic barrier.
• Stool collected from patients who ingested barium sulfate, bismuth compounds, mineral oil, antacids, or radiopaque contrast media within the preceding 7 days (causes extensive crystalline debris obscuring microscopic fields).
• Unpreserved liquid or diarrheal stool delivered more than 30 minutes post-defecation.
• Unpreserved formed stool delivered more than 2 hours post-defecation.

5.4 Daily Internal Quality Control (IQC) Governance

` Clinical Microscopy Daily IQC Workflow | +---> Urine Chemistry Analyzer (Sysmex UC-1000): | Run Sysmex UC-CONTROL-L (Low / Normal) | Run Sysmex UC-CONTROL-H (High / Abnormal) | Verify against manufacturer target ranges before patient testing | +---> Rapid Test Cassettes (hCG, H. pylori, FOBT): | Verify Control Band (C) on every patient cassette | Lot-to-lot positive & negative control verification upon receipt | +---> Centrifuge & Microscope: Check 400 x g (1500-2000 rpm) timer and smooth deceleration * Clean optical lenses, align condenser, and check illumination `

5.4.1 Urinalysis Reagent Strip Quality Control

• Run daily Sysmex UC-CONTROL-L and UC-CONTROL-H quality control using two levels of commercial liquid urine control: Sysmex UC-CONTROL-L (Level 1 Low/Normal) and Sysmex UC-CONTROL-H (Level 2 High/Abnormal).
• Test both levels of UC-CONTROL every morning before analyzing patient specimens, upon opening a new bottle or lot of Sysmex MEDITAPE UC-10S test strips, and following any optical window cleaning or instrument maintenance.
• Remove control vials from 2 to 8 °C refrigerator, allow to equilibrate to room temperature (18 to 25 °C) for 15 minutes, mix gently by inversion, and apply to test strips following the exact dipping protocol.
• Check that all ten parameters fall within manufacturer target ranges printed on the lot-specific package insert. Record results on Electronic QC log under Quality Control Policy (registered under F-QM-002-B-V0).

5.4.2 Qualitative Rapid Immunoassay Controls

• For Abbott Bioline hCG, RightSign H. pylori, and FOBT cassettes, verify that the Control Band (C) appears as a distinct colored line in the Control (C) zone on every patient cassette. This confirms adequate specimen volume, proper membrane wicking, and reagent binding. A cassette lacking a visible C line is invalid and shall never be reported.
• Test positive and negative external controls whenever a new kit lot or shipment is opened, when storage conditions exceed allowable temperature ranges, or when test cassette integrity is questionable.

5.4.3 Corrective Actions for Quality Control Failure

• Halt patient testing; inspect strip bottle and log nonconformance on F-QM-010-A-V0 whenever any IQC parameter or procedural control band fails.
• Inspect strip bottle desiccant, lot numbers, expiration dates, and analyzer optical paths.
• Repeat the control run using freshly opened control material or a fresh test strip.
• If the control failure persists, notify the Chief Medical Technologist / Laboratory Quality Manager, log the nonconformance on F-QM-010-A-V0, and do not release patient results until acceptable performance is documented.

5.5 Result Correlation and Analytical Validation Rules

Before authorizing any Clinical Microscopy report, the examining Medical Technologist shall perform correlation checks between physical, chemical, and microscopic findings:

• Correlate Blood, Leukocyte Esterase, Nitrite, and Protein with sediment findings.
• If a discrepancy between chemical dipstick and microscopic findings occurs, investigate lysis, ascorbic acid, or non-nitrate reducers per discrepancy protocol before releasing reports.

5.6 Specimen Retention and Biohazard Waste Disposal

• Store recapped urine refrigerated at 2 to 8 °C for at least 24 hours per LAB-QM-POST-004. Following analysis and result release, patient urine specimen tubes shall be recapped, maintained in designated wire racks, and stored in the section refrigerator at 2 to 8 °C for at least 24 hours per Laboratory Retention Schedule Policy. This allows repeat testing in case of clinical inquiry or discordant findings.
• Retain stool specimens refrigerated at 2 to 8 °C until the end of the working shift (minimum 8 hours). Stool samples exhibiting unusual parasites or referred for pathologist review are preserved in 10% formalin if long-term storage is required.
• For liquid waste disposal, carefully pour residual urine into the designated laboratory disposal sink under running water while wearing protective gloves, gown, and full-face shield. Flush the sink with water and sanitize with 0.5% sodium hypochlorite solution daily.
• For solid biohazard waste disposal, discard used urine cups, centrifuge tubes, transfer pipettes, stool containers, applicator sticks, test strips, and rapid cassettes into heavy-duty yellow biohazard waste bags labeled with biohazard symbols.
• For sharps disposal, place microscope glass slides, coverslips, and broken glass immediately into rigid, puncture-proof yellow sharps containers per Laboratory Safety Policy.

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 7.2 — Pre-examination processes
• ISO 15189:2022, Section 7.3 — Examination processes
• ISO 15189:2022, Section 7.4 — Post-examination processes
• WHO Laboratory Quality Management System Handbook, Chapter 5 — Process Control
• CLSI GP16-A3, Urinalysis — Approved Guideline
• CLSI M28-A2, Procedures for the Recovery and Identification of Parasites from the Intestinal Tract

Companion policies:

• Scope of Service and Laboratory User Information Policy — Laboratory test menu and Clinical Microscopy diagnostic service scope
• LAB-QM-PRE-001 — Specimen identification, acceptance criteria, and rejection management
• Laboratory Retention Schedule Policy — Laboratory records, worksheets, and specimen retention schedules