INTRODUCTION TO LABORATORY
MEDICINE
DEFINITION
Laboratory medicine a specialty in which
pathologists provide testing of patient samples
(usually blood or urine) in several different
areas.
Determination of the level of enzymes in blood in case
of heart attack or
 Level of glucose (sugar) in the blood of a patient with
diabetes.
 The presence of bacteria and other microorganisms.
 Blood cells studies for various types of anemias
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COURSE CONTENTS
Clinical Biochemistry
 Cardiac profiles
 Liver and renal panels
 Bone metabolism
 Lipid chemistry
 Special chemistry
 Cardiovascular markers
 Tumour markers
 Nutritional markers
 Calculi

Immunology and Immunodiagnostics
 Drug monitoring
 Urine and serum proteins
 Autoimmune disease testing
 Endocrinology tests
 Fertility testing
 Point-of-Care Testing
 Cardiac markers
 Glucose monitoring program
 Blood gases and metabolites
 Routine chemistry panels
 Routine urinalysis and pregnancy screening
 Coagulation
 Complete Blood Counts
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
Urine toxicology screening
Laboratory Hematology
 Routine and special hematology
 Hemoglobinopathy studies
 Special stains
 Hematopathology
 Bone marrow consultations and interpretive
report
 Special coagulation
 Coagulation profiles, screening and factors and
inhibitors
 Platelet studies
 Thrombophilia testing

Microbiology
 Infection control
 Reference centre for medical microbiology and
infectious diseases
 Detection and typing of epidemiologically
significant organisms
 Molecular Diagnostic Testing
 Blood Bank/Donor Center
 Concepts of immunohematology and
histocompatibility
 Blood transfusion services and quality
assurance
 Blood donation and storage of blood
 Blood grouping
 Compatibility testing
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RECOMMENDED BOOKS
Textbook:
Clinical biochemistry an illustrated color
atlas by Allan Gaw
District laboratory practice in tropical
countries by Monica Cheesbrough.
Clinical chemistry by William J Marshall.
Reference books:
Medical Laboratory technology by Ramnik
Sood.
REASONS FOR ORDERING TESTS

Confirm diagnosis

Aid in diagnosis

Evaluate prognosis

Monitor therapy

Screen for a disease
SECTIONS OF THE LABORATORY
CLINICAL
PATHOLOGY
1. Clinical Chemistry
 Liver profile
 Lipid profile
 Glucose profile
Special chemistry
(endocrinology, fertility)
2.Clinical Microscopy
 Analysis of body fluids
 Urin analysis
 Fecal anaysis
 Semen analysis
3. Microbiology
Cultures (sputum,
blood, urine)
 Sensitivity tests
4. Hematology

Biggest section
Includes CBC,coagulation,
PT, APTT
Blood bank
Serology/Immunology
Very critical section
Bec. May have errors

Blood typing
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Cross match

Cardiac and thyroid fxntest
II. ANATOMY PATHOLOGY
Goes hand in hand with serology
and immunology
Tests done for

MALARIA

SYPHILIS

HIV
Histopathology
CIRCUIT DIAGRAM OF CLINICAL
BIOCHEMISTRY PROCESS
SAMPLE

A sample of a material to be tested or analyzed
that is prepared from a gross sample and retains
the latter's composition.
SPECIMENS WHICH ARE USED IN LAB
FOR TESTING
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Venous blood, serum or plsma.
Arterial blood
Capillary blood
Urine
Faeces
Cerebrospinal fluid
Sputum and saliva
Tissue and cells
Calculi
Aspirates e.g.
Pleural fluid
Ascites
 Synovial fluid
 Intestinal
 Pancreatic
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NATURE OF REQUEST
STAT
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Performed immediately
and by itself
Run control and
standard
20-50% More expensive
TAT is shortened
Request is needed
Today
 Confusing
 Performed as soon as
possible, given
priority
 Based on “running
time”
Routine
 Done with the batch
 Wait for TAT stated
by laboratory
AUTOMATION AND COMPUTERIZATION

Test Repertoire (Range)
More than 400 tests can be performed in the lab
 Analyzers
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Laboratory personnels
VALUES
REFERENCE VALUES
 Better term than
“normal value”
 Pulled value, usually
95%of population
 Vary in diff. hospitals
but not that far
SIGNIFICANT
VALUES
 Clinical decision should
be made if higher
or lower than reference
value
 Usually when 2x to 3x
CRITICAL VALUES
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Needs immediate attention
“panic values”
Should call physician
Patient is at risk
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Glucose less than 45mg/dl
More than 500mg/dl
Potassium less than 6.6 g/dl
More than 19.9 g/dl
REFERENCE VALUES
Not fixed for all
Should consider:
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Age
Sex
Pregnancy
Diurnal Variation
Race
Blood type
ROUTINE EXAMINATIONS
ROUTINE ADMISSION TESTS
CBC, Urinalysis, Fecalysis
ROUTINE CHEMISTRIES
BUN, Creatinine, Glucose, Uric Acid, Cholesterol
Sometimes triglycerides
SPECIMEN COLLECTION
Correct sample
 Correct information (history)
 More information is required while reassessing or
assessing prognosis.
 Identification must be clear and correct.

QUALITY ASSURANCE TO OBTAIN
CORRECT TEST RESULTS
Immediate and long term clinical, public health, and
health planning decisions are based on the results of
laboratory tests. Incorrect, delayed, or misinterpreted
test results can have serious consequences for
patients and communities, undermine confidence in
the service, and waste scarce district health
resources.
 Achieving reliability of test results is dependent on:
 Understanding what are the commonest causes of
inaccuracy and imprecision in the performance of
tests and of delayed or misinterpreted
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and sources of error). Taking the necessary steps to
prevent and minimize errors by:
– implementing Standard Operating Procedures (SOPs)
with quality control for all district laboratory activities.
– introducing every month a quality control day and an
external quality assessment scheme for outreach
laboratories (see later text, Role of the district medical
officer in TQM).
– appointing a district laboratory coordinator to monitor
the performance of district laboratories (see later text).
Agreeing with those requesting laboratory tests, policies of
work that will enable the laboratory to provide an efficient,
safe, cost-effective, and reliable service (see subunit 2.4).
Maintaining good communications between laboratory
staff and those requesting tests.
REFERENCE RANGES FOR
QUANTITATIVE TESTS