Medical Laboratory Science – Week 2 Comprehensive Notes

Definition & Terminology

  • Medical Laboratory Science (MLS) / Clinical Laboratory Science (CLS)

    • Study & practice of diagnostic testing on human body fluids.

    • Other synonymous terms: Medical Technology (MT), Clinical Pathology.

  • Body fluids commonly tested

    • Blood (whole, serum, plasma)

    • Urine, feces, sweat, tears, semen

    • Cavity fluids: amniotic, synovial, pericardial, peritoneal, pleural, cerebrospinal, etc.

MLS vs MLT

  • MLS (Medical Laboratory Scientist)

    • Requires a 44-year Bachelor of Science in MLS.

    • Must pass the ASCP national board exam.

    • Authorized to work as a generalist across all 55 clinical pathology disciplines & may release results.

  • MLT (Medical Laboratory Technician)

    • Requires a 22-year Associate of Science.

    • Must pass the ASCP national board exam.

    • MLS usually assumes broader responsibilities than MLT due to greater depth & breadth of training.

Components of a Diagnostic Laboratory

  • Clinical (Clinical Pathology)

    1. Hematology / Coagulation

    2. Clinical Chemistry / Urinalysis & Body Fluids

    3. Medical Microbiology

    4. Immunohematology (Blood Bank)

    5. Immunology / Serology

  • Anatomical Pathology

    1. Cytology

    2. Histology

    3. Cytogenetics

Anatomical Pathology Focus

  • Cytology

    • Examines groups of cells obtained by fine-needle aspiration (FNA), Pap smears, flow cytometry of fluids (pleural, CSF, etc.)

  • Histology

    • Microscopic study of tissues.

    • Process: Fix

    • Slice

    • Stain

    • Microscopic review.

  • Cytogenetics

- Analyzes chromosomal structure, number & DNA abnormalities (structural / numerical, mutations, specific sequences). Focus: detection, grading & staging of neoplasms / cancers.

  • Each sub-discipline has dedicated training programs & its own national board.

Five Core Clinical Pathology Disciplines

  1. Hematology & Coagulation

    • Counts WBCs, RBCs, platelets; evaluates clotting ability.

    • Classic test: Complete Blood Count (CBC).

  2. Clinical Chemistry, Urinalysis & Body Fluids

    • Measures electrolytes, enzymes, hormones, lipids, proteins, metabolites.

    • Panels: Basic Metabolic Panel (BMP), Comprehensive Metabolic Panel (CMP).

  3. Medical Microbiology

    • Detects pathogenic microorganisms in blood, urine, feces, sputum, etc.

    • Culture & antimicrobial (antibiotic) sensitivity testing.

  4. Immunohematology (Blood Bank / Transfusion Service)

    • Blood collection, processing, storage.

    • Compatibility testing for transfusion (ABO/Rh typing, cross-match).

  5. Immunology & Serology

    • Evaluates antibodies, antigens, immune cells (T-cells, B-cells), cytokines for disease diagnosis & monitoring.

    • MLS generalists are trained to perform in all five areas.

Clinical Pathology Specialties

  • Molecular Diagnostics

    • DNA/RNA analysis.

    • Techniques: Polymerase Chain Reaction (PCR), Fluorescence In Situ Hybridization (FISH), Next-Generation Sequencing (NGS).

  • Clinical Toxicology

    • Diagnosis & management of poisoning; assesses adverse effects of drugs & chemicals.

Typical Laboratory Staffing Structure

  • Administrative Lab Director

    • strategic oversight, quality & financial performance.

  • Technical Lab Director / Medical Director

    • clinical pathologist or PhD; accountable for technical quality & results.

  • Lab Manager

    • day-to-day operations, purchasing, staffing, regulatory compliance.

  • Lab Supervisors

    • head specific departments.

  • Medical Laboratory Scientist (MLS)

    • performs tests & releases verified results.

  • Medical Laboratory Technician (MLT)

    • performs tests.

  • Medical Laboratory Assistant (MLA)

    • specimen transport, centrifugation, stocking, instrument QC loading.

  • Phlebotomist

    • venipuncture & specimen collection.

Units Within the Clinical Laboratory Workflow

  1. Specimen Labeling & Collection

    • Positive patient ID using ≥2\ge 2 unique identifiers (e.g., name & DOB).

    • Venipuncture at antecubital fossa for blood; collection of urine & other fluids.

  2. Specimen Accessioning & Processing

    • Integrity check, LIS entry, unique accession number assignment, possible centrifugation.

  3. Testing Departments

    • Hematology, Chemistry, Microbiology, Blood Bank, Immunology/Serology, Molecular Diagnostics.

  4. Data Management

    • LIS configuration, analyzer interfaces, HIS communication, EMR result delivery.

Testing Process Phases

  • Pre-Analytical: patient prep, positive ID, collection, integrity maintenance.

  • Analytical: standardized instrument operation, operator competence, QC, testing.

  • Post-Analytical: result calculation/printing, electronic interfacing, verification, communication.

MLS Generalist vs Specialist

  • Generalists rotate among all five departments; specialists may remain in blood bank, microbiology, chemistry, or hematology exclusively depending on job requirements.

Data Management & Information Systems

  • LIS (Laboratory Information System)

    • Manages orders, collection logs, results; interfaces with analyzers & HIS.

  • EMR/EHR

    • Receives verified results for provider access.

    • Leading vendor systems: EPIC (EPIC Beaker), CERNER (Millennium PathNet).

End-to-End Specimen Flow Summary

  1. Provider enters lab order in HIS.

  2. Specimen labeled & collected

    • delivered to lab.

  3. Accessioning: verify ID/integrity, assign accession #.

  4. Sent to appropriate dept

    • analyzed (manual/instrument).

  5. Results reviewed (manual or autoverification); repeats or recollects if necessary.

  6. Verified results released to LIS

    • EMR

    • provider review.

Educational Accreditation

  • NAACLS (National Accrediting Agency for Clinical Laboratory Sciences)

    • Accredits MLS, MLT, Cytology, Histology, Cytogenetics & related programs.

    • Ensures curricula remain current & comprehensive.

Laboratory Accreditation Bodies

  • College of American Pathologists (CAP)

  • The Joint Commission (TJC)

  • Commission on Office Laboratory Accreditation (COLA)

  • Association for the Advancement of Blood & Biotherapies (AABB)

Certification Organizations (Board Exams)

  • ASCP (American Society for Clinical Pathology)

    • gold standard; CMP (Credential Maintenance Program) every 33 yrs.

  • AMT (American Medical Technologists)

  • AAB (American Association of Bioanalysts)

Professional Organizations

  • ASCLS (American Society for Clinical Laboratory Science)

    • advocacy & professional development.

  • AAB

    • certification & advocacy.

  • AABB

    • blood safety & policy.

  • ADLM (formerly AACC)

    • clinical chemistry & diagnostics advocacy.

Safety & Regulatory Environment

Occupational Safety & Health Act (1970)

  • Established NIOSH (research) & OSHA (standards & enforcement).

  • Employers must provide hazard-free workplaces (chemical, mechanical, noise, temperature, sanitation).

OSHA in the Clinical Lab

  • Mandates PPE (gloves, safety glasses, lab coats, respiratory protection).

  • Requires:

    • Chemical Hygiene Plan (CHP)

    • Lock-Out/Tag-Out (LOTO) procedures

    • Exposure Control Plan (ECP) for bloodborne pathogens (HBV, HCV, HIV).

  • Worker rights: training in own language, safe equipment, access injury records, non-retaliatory reporting.

  • Training