Introduction of Clinical Laboratory Science

TAPESHWAR YADAV
(LECTURER)
BMLT, DNHE,
M.SC. MEDICAL
BIOCHEMISTRY
Clinical or Medical
Laboratory

A – A good student is liked by teacher
G – Greets everyone with smile
O – Obedient
O – On time for college
D – Dresses neatly
S – Studies with interest
T – Treats everyone with smile
U – Understands everything
D – Does daily home work
E – Eager to know new things
N – Never misbehaves
T – Talks little in class

Introduction
Laboratory is a place that is equipped with different
instruments, equipments and chemicals (reagents) etc., for
performing experimental works, research activities and
investigative procedures.
Medical laboratory is one part of the laboratory that is
equipped with various biomedical instruments,
equipments, materials and reagents (chemicals) for
performing different laboratory investigative activities by
using biological specimens (whole blood, serum, plasma,
urine, stool, etc).

Medical laboratory science
Medical laboratory science is a complex field
embracing a number of different disciplines
such as:
Microbiology,
Hematology,
Clinical Chemistry,
Urinalysis, Immunology, Serology,
Histopathology, Immunohematology and
Molecular biology and others.

Contd…
Immunology,
Serology,
Histopathology,
Immunohematology and
Molecular biology and others.

Medical Laboratory Technology
The practice of modern medicine would be
impossible without the tests performed in the
clinical laboratory.
 A medical team of pathologists, specialists,
scientists, technologists, and technicians work
together to determine the presence, extent, or
absence of disease and provide data needed to
evaluate the effectiveness of treatment.

Clinical or Medical Laboratory
Laboratories that perform chemical and microscopic
tests on:
blood
other body fluids
tissues

Clinical Laboratories
 Play a major role in patient care
 Variety of settings
 Two types of Clinical.Laboratory
 Hospital lab.
 Non hospital lab.
 POLs
 Reference laboratories(LABCORP/QUEST D.)
 Government laboratories - federal
 Center for Disease control and Prevention(CDC)
 Epidemiology labs
 Laboratory Response Network

 Government Laboratories- state
 Premarital blood testing
 PKU testing in newborns
 Fungi,virus, and mycobacteria culture

Regulations of Clinical Laboratory
 All laboratories, but research labs.are regulated by
Federal and State agencies
 CLIA’88- Clinical Laboratory Improvement
Amendments of 1988:
Is a revision to the original CLIA of 1967, specifies
the minimum performance standards for all
Clinical Laboratories

Objectives of CLIA’88
 To ensure quality Laboratory Testing, amendments
are continually revised, updated, clarified and
refined
 CMS:Center for Medicare and Medicaid
Services,agency within the Department of Health
and Human Services responsible for implementing
CLIA’88

CMS
 Any Laboratory performing Lab. tests in humans
,except for research Labs. Must obtain a certificate
from CMS (center for medicare-medicaid services) to
be allowed to operate

Laboratory Personnel
 Director of the Lab.- Pathologist, MD, DO, or hold
a doctorate in a related clinical field. Hold
certification and have supervisory and clinical
laboratory experience
 Technical supervisor/Lab.Manager-someone
educated in the clinical laboratory sciences who
has additional business experience

Laboratory personnel
 General supervisor for each area
 Testing personnel:
 Medical Technologists(MT/CLS)
 Medical Lab.Technicians(MLT/CLT)
 Medical assistants/nursing staff(POLs)

Departments of the Clinical Laboratory
 Clinical Chemistry
 Hematology
 Microbiology
 Blood Bank
 Supports Services (Phlebotomy/Specimen
Processing)

Clinical Chemistry
 Tests perform in serum, plasma, urine and other
body fluids such as spinal fluid, or joint fluid
 Largest department in the Lab.
 Toxicology
 Special chemistry

Hematology
 Studying of the cellular components of the blood
 Quantitative or Qualitative
 Coagulation
 Urinalysis
 Special hematology

Microbiology
 Culture/identification microorganisms
 From sputum, wounds, blood, urine and other body
fluids
 Inoculated in culture media
 Organisms are identified and susceptibility test are
performed
 Bacteriology, virology, serology, parasitology

Blood Bank
 Also called immunohematology or transfusion
services
 ABO group and Rh typing
 Antibody testing
 Storage of packed cells units
 Processing of some components like platelets and
cryoprecipitate

Support Services
 Phlebotomists
 Accessioning

POCT
 Point of care testing brings the laboratory to the
patient, also called bed-side testing
 Use small simple analyzers
 Portable instruments
 Hgb, glucose, electrolytes,and cholesterol

Quality Assessment System
 QA.is incorporated to each department’s procedure
manuals and day to day operation
 Standardized material are analyzed on each
instrument to document precision, and
reproducibility
 Calibration, maintenance and repair of the
instruments is recorded
 Participate in proficiency testing programs

 Health care agencies have very specific
standards, rules and regulations governing the
education and job responsibilities of the
laboratory personnel
 Lab. professionals are required to complete an
authorized program and certification
 Lab. Personnel need to observe/protect patient
privacy

Safety
 Occupational Safety and Health
Administration(OSHA) began in 1970 as a legislation
and subsequent rules that mandate increased
attention to safety in workplaces
 The Clinical laboratory has, physical, chemical and
biological hazards

PPE
 Employees in the clinical lab are required to use
personal protective equipment:
 Gloves
 Mask
 Gowns

Biohazards
 In 1980 clinical laboratory safety training
concentrated in protection from chemical,
physical,and contagious diseases such as
tuberculosis
 The discovery of AIDS, increased in Hepatitis B
virus(HBV) and Hepatitis C virus(HCV) brought an
emphasis on biological safety
 The term Biohazard came into use
 A Biohazard symbol was adopted that indicates the
presence of biological hazard or biohazardous
condition

Evolution on Biological safety
 By 1960 infectious patients were placed in
ISOLATION rooms
 1970-CDC outlined isolation guidelines and listed
isolation categories
 1985-in response to the increasing AIDS/HIV
epidemic CDC adopted Universal Blood and Body
fluids precautions, to be applied in all patients
regardless of their infectious status
 1987- Body substance Isolation, included all body
fluid even if not visibly contaminated with blood

Evolution on Biological safety
 1991-OSHA issued “Bloodborne pathogens
standard”, not included on previous regulation
 1996- CDC implemented “Standard Precautions”
that includes a comprehensive set of safety
guidelines for Health care workers rendering care
to patients, this is the current terminology
 To control nosocomial (inst. acquired) infections
 Transmission-based precautions(additional practices for
pathogens that spread by air, droplets, and contact
2001-OSHA revised the BBP(blood borne pathogen)
standard to prevent accidental needle-sticks in the
workplace

Standard Precautions
Requires that every patient and every body
fluid, body substance, organ, or unfixed tissue
be regarded as potentially infectious
 Hands wash(plain soap)
 After touching body fluids and contaminated items, after
removing gloves and between patient contact
 Wear gloves
 When touching blood/body fluids/secretions, wear clean
gloves when touching mucous membranes and nonintact
skin
 Wear mask/eye protection/face shield
 Activities that could generate splashes, spray of blood, body
fluids , or secretions

Standard Precautions, cont.
Patient care equipment
 should be handled to prevent transfer of
microorganisms to other patients and environment
Linen
 Handle, transport,and process in a manner to avoid
contamination of clothing and other patients or
environment
Occupational health and blood-borne pathogens
 Prevent injuries when using, handling, cleaning and
disposing sharps
 NEVER RECAP A USED NEEDLE
 Do not removed used needle from syringe by hand
 Disposed used sharps on puncture resistant containers

Standard Precautions,cont.
 Use resuscitation devices as an alternative to mouth to
mouth resuscitation
 Patient placement
 Use a private room for patients who can be a source of
contamination or patients who are not expected to
maintain hygiene or environmental control
 Environmental control
 Follow hospital procedures for routine care and
cleaning/desinfection of any soiled device, equipment
or environmental surface

General laboratory equipment
 Centrifuges- spin samples at high speeds
forcing the heavier particles to the bottom of
the container,e.g..separating plasma and blood
cells
 Safety tips
 Use Standard Precautions/PPE
 Load must be balanced
 Tubes must be capped during operation
 Do not open the centrifuge while rotor is moving
 Clean spills immediately with surface disinfectants

Autoclaves- use steam under pressure to sterilize
medical/surgical instruments, or contaminated
materials before disposal
 Never open unless the chamber pressure reads zero
 Use heat-proof gloves to remove items
 When sterilizing liquids use loosely capped, heat resistant
containers, no more than half full
 Use an autoclave tray to prevent liquids from spilling

 Laboratory balances
 Used to measure chemicals
 Use PPE and chemical safety precautions
 Be gentle, Balances are delicate equipment

 Other equipments
 Refrigerators
 Water baths
 PH meters
 Incubators
 Thermometers
 freezer

The Microscope
 Is a delicate and expensive instrument , special
care must be taken in its use
 Various types of microscopes, two categories based
on type of illumination
 Light microscopes
 Bright-field- stained specimens
 Phase-contrast-unstained cells,urine sediment
 Epi-fluorescence microscope,specimens treated with fluorescent
dyes, syphilis, mycobacteria
 Electron microscopes:provides greater magnification in
medical research

Light microscope images
A-stained cell seen with bright field microscope
B-phase contrast image
C-epi-fluorescence microscopy,Borrelia burgdorferi

Parts of the Microscope
Oculars: monocular or binocular
Objective lenses: attached to the revolving nose
piece, at least 3 present: low, high dry, and oil
immersion lenses
Light condenser which focuses and directs light to
the objectives, iris diaphragm that regulates the
amount of light that strikes the object observed
Field diaphragm:help align the light
Coarse and fine adjustments:focusing knobs
Stage:support for the object been viewed

Microscope safety
 Safety
 observe electrical safety rules
 Glass slide handle with care to avoid breaking
 Unfixed specimens should be treated with standard
precautions,disinfect stage after use
 QA
 Scheduled maintenance should be performed and
documented
 Care and cleaning of lenses
 Use only lens paper, clean lenses before and after each use
 Do not allowed immersion oil to touch the low and high dry
lenses
 Transporting and storing

Using the Microscope
 Use low power objective to locate and to view large
objects
 With the coarse adjustment knob bring the objective
and the slide as close together as possible
 While looking through the oculars, move the coarse
adjustment knob to bring the objective and slide apart
until the object on the slide comes into focus
 Use the fine adj.knob to bring the image into sharp
focus

Using the Microscope
 If you need to use the high power(40x), to see cells
and sediments, after initial focusing with the low
power(20x), rotate the high power into position
 Never use the coarse adjustment knob with high
power, the distance between the objective and slide is
very small and the slide could break.
 Oil immersion lenses(100x) give the highest
magnification of the bright field objectives

Using oil immersion lenses
 After initially focusing with the low power, rotate
the objective to the side and place a small drop of
immersion oil on the slide
 The oil immersion objective is rotated into the drop
of oil been careful no other objective touch the
oil
 use only fine adjustment knob with oil
 Condenser should be all the way up
 Maximum light source
 Open the iris diaphragm to the maximum

After using the Microscope
 Always switch to the low magnification objective
 With lens paper clean the oil immersion objective,
stage and condenser if oil has become in contact
with it
 Turn the light source off
 Unplug the microscope
 Store in proper location or cover as appropriate

Calculate Magnification
 Degree of magnification on the ocular multiplied
by the degree of magnification on the objectives
Example:
10x(ocular) x 100x(oil immersion)= 1000x
The object viewed would be magnified
1000 times its original size
Resolving power: the ability of a microscope to
produce separate images of closely spaced details
in the object being viewed

Blood collection
 Capillary puncture: small amount of blood collected for
glucose, K, electrolytes, Hgb, Htc, Plt count, or when a
larger sample is difficult to obtain as in newborns
 Routine venipuncture: most common method of
obtaining blood, a superficial vein is punctured with a
hypodermic needle and blood is collected into a syringe
or vacuum tube

Capillary Puncture
 Safe
 Quick
 Small amount of blood
 Increased use
 Point-of-care testing (POCT)
 Physician Office Laboratories

Capillary Puncture Sites
 Fingertip
 Great toe
 Heel

Lancets
 Sterile
 Single-use
 Different lengths

Routine Venipuncture
 Phlebotomy
 Superficial vein
 Large sample of blood
 Skill and experience
 Preserve vein integrity

Venipuncture Supplies
 Needles
 Various safety designs
 21 ga, 1 inch
 Needle holders
 Phlebotomy tray

Venipuncture Supplies
 Vacuum tubes and anticoagulants
 Sizes
 Stopper color:
 Red: no anticoagulant, to collect serum for blood chemistries
and serology tests
 Lavender: containing EDTA for hematologycal and blood
typing tests(ethylenediaminetetraacetic acid )
 Green: contains heparin, for lymphocytes studies and special
chemistry
 Light blue: sodium citrate for coagulation studies
 Gray :potasium oxalate, for glucose and legal alcohol
 Black: for westergren ESR
 Draw exact amount

Safety Precautions
 Observe standard precautions
 Wear gloves and other PPE
 Never recap needles
 Use proper technique
 Avoid
 Hemoconcentration: do not leave tourniquet in place for
more than 1-2 minutes
 Hemolysis: do not shake tubes, mix by gently inverting a
few times

Patient Preparation
 Patient I.D.
 Explain procedure
 Support patient and arm
 Be prepared! for any sudden reaction from the
patient, or occasional patient who may faint

Apply Tourniquet
•3-4 inches above
elbow
•Use quick release
tie

Identify Suitable Vein
 Veins commonly used
 Median cubital
 Basilic
 Cephalic
 Palpate vein:
carefully inspect
both arms to find
the better site

Perform Venipuncture
 Alcohol-cleanse site, let air dry, do not touch the
site after cleaning
 Observe bevel up
 Anchor vein with thumb 1inch below the
puncture site
 Enter vein in the same direction of it, in a15-25
degree angle, in a smooth motion
 Insert vacuum tube
 Clot tube first
 Invert anticoagulant tubes softly 5-7 times

Adverse situations
 In case of patient developing a large hematoma while
venipuncture procedure is being done, withdraw the
needle, apply pressure, and intent the procedure in a
different site
 In case of failure to obtain the blood, ask the patient
permission for a second intent, if he agrees try in a
different site
 After the second non-productive intent,inform the
patient and find another person to draw the specimen

Complete Procedure
 Activate safety feature
 Immediate disposal
 Label tubes before leaving the room
 Patient care

Patient care
 The tourniquet is always release before needle is
withdraw
 Gauze should be applied over the puncture site and
pressure maintained for 1-3 minutes or until
bleeding stops
 Ask patient to keep arm extended
 Offer a small bandage if necessary

In Case of Accident
 Immediately clean exposed area
 Flood with water
 Clean with antiseptic soap
 Report immediately to supervisor
 Seek medical attention

Label the samples
 Must contain patient information
 Name
 Date of birth
 Date and time of collection
 And initials of the person drawing the blood
 Tubes should never be prelabeled to avoid using the
prelabeled tube in the wrong patient
 Make sure the tubes are clean and no blood has
contaminated the outer part of the tubes
 Place specimen in a biohazard labeled bag and proceed as
required by the institution

selecting tests to use:
 Test selections are based on :
 subjective clinical judgment,
 national recommendations,
 and evidence-based health care.
 Often diagnostic tests or procedures are used as
predictors of surgical risk or morbidity and mortality
rates because, in some cases, the risk may outweigh the
benefit.

selecting tests to use:
1.Basic screening (frequently used with wellness
groups and case finding)
2. Establishing (initial) diagnoses
3. Differential diagnosis
4. Evaluating current medical case management
and outcomes
5. Evaluating disease severity

6. Monitoring course of illness and response to
treatment
7. Group and panel testing
8. Regularly scheduled screening tests as part of
ongoing care
9. Testing related to specific events, certain signs and
symptoms, or other exceptional situations (eg, infection
and inflammation , sexual assault, drug screening,
postmortem tests, to name a few)

groups and case finding)
 Cervical Papanicolaou (Pap) test
 Yearly for all women 18 years of age; more often with
high-risk factors (eg, dysplasia, human
immunodeficiency virus [HIV], herpes simplex);
check for human papillomavirus (HPV), chlamydia,
and gonorrhea using DNA

Establishing (initial) diagnoses
 Serum amylase
 In the presence of abdominal pain, suspect pancreatitis
 Thyroid-stimulating hormone (TSH) test
 Suspicion of hypothyroidism, hyperthyroidism, or thyroid
dysfunction in patients 50 years of age

Differential diagnosis
 Chlamydia and gonorrhea
 In sexually active persons with multiple partners; monitor for
pelvic inflammatory disease

Evaluating current medical case
management and outcomes
 Tuberculosis (TB) blood test QuantiFERON Gold TB
 Blood test to assess TB exposure in risk population
 Syphilis serum fluorescent treponemal antibody
(FTA) test
 Positive rapid plasma reagin (RPR) test result

Grading Guidelines for Scientific
Evidence
 A. Clear evidence from all appropriately conducted
trials
 Measure plasma glucose through an accredited lab to diagnose or
screen for diabetes
 B.Supportive evidence from well-conducted studies or
registries
 Draw fasting blood plasma specimens for glucose analysis

 C.No published evidence; or only case,
observational, or historical evidence •
 Self-monitoring of blood glucose may help to achieve better
control
 E.Expert consensus or clinical experience or
Internet polls
 Measure ketones in urine or blood to monitor and diagnose
diabetic ketoacidosis (DKA) (in home or clinic)

The diagnostic testing model
 incorporates three phases:
 pretest,
 emphasis on appropriate test selection,
 obtaining proper consent,
 proper patient preparation,
 individualized patient education,
 emotional support, and effective communication.
 These interventions are key to achieving the desired outcomes
and preventing misunderstandings and errors.

 Intratest Phase: Elements of Safe, Effective,
Informed Care
 Posttest Phase: Elements of Safe, Effective,
Informed Care

The clinical value of a test is related to
 sensitivity, specificity, and the incidence of the
disease in the population tested.
 Sensitivity and specificity do not change with
different populations of ill and healthy patients
 The predictive value of the same test can vary
significantly with age, gender, and geographic
location.

 Specificity refers to the ability of a test to identify
correctly those individuals who do not have the
disease.
 The division formula for specificity is as follows:
 Specificity%=persons w/o dis.who test neg./total #
of persons w/o dis. X 100

 Sensitivity refers to the ability of a test to
correctly identify those individuals who truly
have the disease.
 The division formula for sensitivity is as follows:
 Sensitivity% = persons with dis.who test
positive/ total # persons tested with disease x
100

 Incidence refers to the number of new cases of a
disease, during a specified period of time, in a
specified population or community.
 Prevalence refers to the number of existing cases
of a disease, at a specific period of time, in a
given population.

Predictive values
Predictive values refer to the ability of a screening
test result to correctly identify the disease state.
The predictive value of the same test can be very
different when applied to people of differing ages,
gender, geographic locations, and cultures.

test outcome deviations
Minimize test outcome deviations
 following proper test protocols.
 Make certain the patient and his or her significant others know
what is expected of them.
 Written instructions are very helpful.

Reasons for deviations may include the
following
 Incorrect specimen collection, handling, storage, or
labeling
 Wrong preservative or lack of preservative
 Delayed specimen deliver

Reasons for deviations may include the
following
 Incorrect or incomplete patient preparation
 Hemolyzed blood samples
 Incomplete sample collection, especially of timed
samples
 Old or deteriorating specimens

Patient factors that can alter test results
may include the following
 Incorrect pretest diet
 Current drug therapy
 Type of illness.
 Dehydration
 Position or activity at time of specimen collection

 Postprandial status (ie, time patient last ate)
 Time of day
 Pregnancy
 Age and Gender

 Level of patient knowledge and understanding of
testing process
 Stress
 Nonadherence or noncompliance with
instructions and pretest preparation
 Undisclosed drug or alcohol use

avoid costly mistakes
 Communication errors account for more incorrect
results than do technical errors.
 Properly identify and label every specimen as soon as
it is obtained.

Educate the patient and family
 Educate regarding the testing process and what will
be expected
 Record the date, time, type of teaching, information
given, and person to whom the information was
given.

 Giving sensory and objective information that relates
to what the patient will likely physically feel and the
equipment that will be used is important so that
patients can envision a realistic representation of
what will occur.

 Avoid technical and medical jargon
 and adapt information to the patient's level of
understanding.
 Slang terms may be necessary to get a point across.

 Encourage questions and verbalization of feelings,
fears, and concerns
 Do not dismiss, minimize, or invalidate the patient's
anxiety
 Develop listening skills, and be aware of nonverbal
signals (ie, body language)

 Above all, be nonjudgmental.
 Emphasize that there is usually a waiting period (ie,
turn-around time) before test results are relayed
back to the clinicians and nursing unit.
 Offer listening, presence, and support during this
time of great concern and anxiety

 Because of factors such as anxiety, language barriers,
and physical or emotional impairments, the patient
may not fully understand and assimilate instructions
and explanations

 To validate the patient's understanding of what is
presented, ask the patient to repeat instructions
given to evaluate assimilation and understanding of
presented information.

normal or reference values
 Normal values are those that fall within 2 standard
deviations (ie, random variation) of the mean value
for the normal population.
 Normal ranges can vary to some degree from
laboratory to laboratory. Frequently, this is because
of the particular type of equipment used

 The reported reference range for a test can vary
according to the laboratory used, the method
employed, the population tested, and methods of
specimen collection and preservation.

 Interpretation of laboratory results must always be
in the context of the patient's state of being.
 Circumstances such as hydration, nutrition, fasting
state, mental status, or compliance with test
protocols are only a few of the situations that can
influence test outcomes.

clinical laboratory data values
 may be reported in conventional units, SI
units(Systéme International (SI) units), or both
 The SI system uses seven dimensionally independent
units of measurement to provide logical and
consistent measurements

clinical laboratory data values
SI concentrations are written as amount per volume
 (moles or millimoles per liter)
 rather than as mass per volume (grams, milligrams,
or milliequivalents per deciliter, 100 milliliters, or
liter)

 Numerical values may differ between systems
or may be the same.
 For example, chloride is the same in both
systems: 95 to 105 mEq/L (conventional)
 and 95 to 105 mmol/L (SI).

Recognize margins of error
 possibility exists that some tests will be abnormal owing
purely to chance
 because a significant margin of error arises from the
arbitrary setting of limits.
 Moreover, if a laboratory test is considered normal up to
the 95th percentile, then 5 times out of 100, the test will
show an abnormality even though a patient is not ill

Cultural Sensitivity
 Many cultures have diverse beliefs about diagnostic
testing that requires blood sampling
 Preserving the cultural well-being of any individual
or group promotes compliance with testing and
easier recovery from routine as well as more invasive
and complex procedures

Introduction of Clinical Laboratory Science

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