1. INTRODUCTION ,COURSE
OVER VIEW
MLS Level 7
Ms.Elham Ali Saad

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)

11. Types of results obtained in the
laboratories

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

27.  THANK YOU 