2. Objectives
• Discuss different type of patient’s sample
• Define&Explain substance of clinical interest in many different
situation
• List Component of each test ?
• Compare between different Types of results obtained in the
laboratories
• Compare between different Types of tests in clinical laboratories?
• Describe different Types of equipment & instruments are used in
clinical laboratories
• Discuss Important consideration in using tests, equipment's &
instruments
3. Function of the clinical lab
• Carry out analysis and investigations on patient’s
samples upon to request of the doctor to obtain
meaningful and timely results which will help the doctor
in the proper diagnosis , treatment and management of
the patient condition .
4. • The patient sample can be any type
of material obtained from the patient
which include;
-Whole blood -plasma -serum
-CSF -synovial fluid
-Amniotic fluid -saliva -pericardial fluid
-sweat -sputum -plural
fluid
-peritoneal fluid -semen -body swabs
-urine -Body tissues (biopsies
and needle aspirations)
5. • Substances of clinical interest are those which are
affected directly or indirectly by the disease.
• The effect of disease on such substances can be
increase , decrease or presence of the substance
• Components of tests:
patients sample+ specific reagents+ means of identification
6. • Substances of clinical interest that may be increased
or decreased due to disease include;
-RBC -WBC -platelets -Hb -Hct -PT
-PTT -Na -K -Cl -Ca -Mg
-PO2 -PCO2 -glucose -protein -albumin
-γ-globulin (IgG , IgM , IgA)
-Enzymes (ALP , AST , ALT , GGT….)
-Ammonia -urea -creatinine -cholesterol -TG
-Hormones (cortisol , aldosterone , GH ,T3 , T4 , PTH….)
7. • Substances of clinical interest that their presence
may indicate the presence of disease include;
-Bacteria -Parasites -Viruses
-Tumor Markers (AFP , CEA , PSA…)
-Abnormal cells or tissues
8. • Reagents of the test include:
-Diluent (H2o , 0.9%NaCl , other solutions)
-Solvents (ethanol, acetone, iso-butanol,
petroleum ether , other organic and aqueous
solvents)
-Dyes (giemsa stain, wright stain, BCG,
hemotoxylin, gram stain , malachite green…)
-Buffer : are used when the reaction required
specific pH (acidic , neutral or alkaline pH)
9. -Catalysts :
Used to lower the energy requirement for the progress of
the reaction and speed up the reaction
It can be chemicals or substances such as : (Mg, Ag, Urea ,
Caffeine)
They can be also biological (i.e. enzymes) such as
(dehydrogenases , oxidases , reducates)
10. -Reaction solution:
Are chemicals which are prepared at specified
concentration with specific procedure.
They could be just one single compound (AgCl ,HClO4
, H2O2)
In many cases , the reaction solutions involve two or
more compounds which are added in one step (e.g.:
biuret reagent (protein) , jaffe-reagent (creatinine)
12. Types of tests
1- Screening tests:
Characteristic Simple test
Cheap to perform
involve 1 single step;(mixing 1 drop of
sample + 1 drop of reagent = formation of
product by visual means (naked ye or light
microscope).
Aim of this
type
applied to screen for the presence or
absence of specific disease or disorder
Place to
performed
outside the lab or hospital
13. Requirements
Require minimum amounts of reagents and
equipment's
Don’t require high technical skills
Results
quickly and clearly obtained
Results can be easily interrupted
either qualitative or semi-quantitative
Results obtained are +ve results must be
confirmed by further more and accurate
specific results.
14. 2- Confirmatory Tests:
Characteristic More complex and number of steps
Tests are more sensitive and specific
than screening test
Aim of this type Are used to confirm the positive results
obtained from screening test
Requirements
Require specialized equipments and
instruments
Are performed in the lab
Require technical skills and experience
15. Results
Results more accurate and precise than
screening test
Results can be qualitative , semi-quantitative
or quantitative
If the results is also +ve then the patient is
referred for medical examination
If the results is negative , then the disease or
disorder is ruled out (no disease)
16. 3- Diagnostic tests:
Characteristic expensive and technically demanding
not necessary confirmatory tests but
confirmatory test may be diagnostic
Examples:
- High level of amylase in both blood and urine are
diagnostic for acute pancereatitis
- High level of HCG in women is diagnostoc for
pregnancy
- High level of urea and creatinine are diagnostic foe
renal abnormality
- Low level of cortisol in blood is diagnostic for
addison’s disease
- High level of glucose in GTT are diagnostic for diabetes
mellitus
17. Place of
performed
Usually performed in the lab
Aim of this
type
check for specific substances which are
indicative for the presence of disease or
disorder.
Requirements
Require skill , experience, and good
background of pathophysiology of the disease
Require instruments and equipments of high
accuracy and precision
Require tests with high sensitivity and
specificity
18. Results Can be qualitative , semi-quantitative or
quantitative
In quantitative and semi-quantitative results
the severity of the disease may be related
to the level of the substance
19. 4- Definitive test:
Characteristics Highly advanced, specialized and complex
procedures
They include ; PCR , Mass-spectroscopy ,
HPLC , GC
Aim of this
type
1-Detection of inherited disorder such as; a.a
metabolism abnormalities, f.a metabolism
abnormalities, cystic fibrosis , muscular
dystrophy ,coagulation abnormalities , Hb
abnormalities and many other.
2-It is also being applied to detect the presence
of viruses , bacteria and other microorganisms
20. Aim of this type
3-detect the presence of specific causative
agents such as ; genes , gene mutations ,
specific metabolites or specific cells
This type of tests are able to show disease
variations
Requirements
high level of technical skill , good
experience and background on advanced
techniques
high complex and advanced instruments and
equipments
Results Usually qualitative
21. Types of equipments and
instruments are used in clinical
laboratoriesA)Basic equipments :
Example
- Pipette -Glassware
- -Plastic ware
-Mixer -Balances
-Fridge -Safety cabinet
-Freezer -Fume-cupboard
-Centrifuge
22. B)Single application instruments:
-Example:
light microscope -spectrophotometer
single channel counter
single test analyzers (PH Pco2,Po2 , Na, K , Cl,
Hb-meter)
-Can be linked to computer for operations and
results
-Very important in high capacity(large) laboratory
23. -Reduce the amount of time ,effort and
space required for tests.
-Example
1-automated hematology analyzer :
measure RBCs , WBCs ,platelets , Hb,
Differential , Hct , and calculate MCV ,
MCHC)
2-automated chemistry
analyzer(measure number of analytes
24. C) Multi-tests (multi-sample instruments):
-usually fully or partially automated
-Can carry out more than one measurements
-Can process many samples
-Depend on electronic and computer controls
-Combine various technique and instruments in one large
system as :
(pipetting+spectrophotometer+ISE+incubator+mixer+
Washing + centrifugation+calculation)
25. Important consideration in using
tests , equipment's & instruments
-title/name -purpose and aim
-principle of operation the instruments
-principle of test -proper methodology
-reagent preparation -type of specimen
-collection and handling of specimen
-transportation
-processing and storage of specimen
-precaution and source of errors
26. -safety consideration(electrical, fire,biological,chemical ,waste)
-use of standards , calibrators and controls
-results calculation and interpretation
-installation and maintenance of instruments
-sensitivity and specificity ,accuracy and precision of test
and instruments .
-updating/changing of tests and instruments
-always time manage and organize your procedures and
instruments
