Lecture 11-qualitycontrolinserology-110711110534-phpapp01

mr-said warsame nur MLS-
UNISO MPH-EPIDEMIOLOGY-DIU 1

 Process or system for monitoring
the quality of laboratory testing,
and the accuracy and precision of
results
 Routinely collect and analyze data
from every test run or procedure
 Allows for immediate corrective
action

 Accuracy refers to the closeness of a measured
value to a standard or known value. For example,
if in lab you obtain a weight measurement of 3.2
kg for a given substance, but the actual or known
weight is 10 kg, then your measurement is not
accurate. In this case, your measurement is not
close to the known value
 Precision refers to the closeness of two or more
measurements to each other. Using the example
above, if you weigh a given substance five times,
and get 3.2 kg each time, then your
measurement is very precise. Precision is
independent of accuracy.

 Quality Control - QC refers to the measures that must be included
during each assay run to verify that the test is working properly.
 Quality Assurance - QA is defined as the overall program that
ensures that the final results reported by the laboratory are correct.
 “The aim of quality control is simply to ensure that the results
generated by the test are correct.
 quality assurance is concerned with much more: that the right test is
carried out on the right specimen, and that the right result and right
interpretation is delivered to the right person at the right time”

 Quality Assessment - quality assessment (also known
as proficiency testing) is a means to determine the quality
of the results generated by the laboratory. Quality
assessment is a challenge to the effectiveness of the QA
and QC programs.
 Quality Assessment may be external or
internal, examples of external programs

 Establish
written policies
and procedures
◦ Corrective
action
procedures
 Train all staff
 Design forms
 Assure
complete
documentation
and review

Purchasing
& Inventory
Assessment
Occurrence
Management
Information
Management
Process
Improvement
Customer
Service
Facilities &
Safety
Organization Personnel Equipment
Documents
& Records
Process
Control
(QC & EQA) &
Specimen
Management

The Quality Assurance Cycle
•Data and Lab
Management
•Safety
•Customer
Service
Patient/Client Prep
Sample Collection
Sample Receipt
and Accessioning
Sample TransportQuality Control
Record Keeping
Reporting
Personnel Competency
Test Evaluations
Testing

 SEROLOGICAL TESTS are performed to
demonstrate antigens in the serum, or the
response of the human body to these
infectious agent ( Antibodies ) to establish
its contact with the immune system.
Serological tests are of importance in
epidemiological studies and to ascertain the
response of the population to vaccines and
other immunopotentiators.

 Serological tests
are of
importance in
epidemiological
studies and to
ascertain the
response of the
population to
vaccines and
other
immunopotentiator mr-said warsame nur MLS-

 Serological tests are
also useful for the
in vitro detection of
microbial
infections, and for
the classification
and sub
classification of
infectious agents
(e.g. Salmonella,
Shigella,
Streptococcus, mr-said warsame nur MLS-

 There must be a system for the
orderly and efficient requesting
of tests; collection and
identification of specimens;
and transporting, preparation,
and storage of specimens.
Nothing is more important than
having an adequate amount of
an appropriate specimen in
good condition for
examination. If each specimen
is not properly collected,
labeled, and handled, or is not
representative, the laboratory
may do more harm than goodmr-said warsame nur MLS-

 Haemolysed blood
specimens are not
suitable for
serological studies.
It is always
advisable to avoid
factors which cause
hemolysis (Table
14.1). Specimens
containing
precipitates should
be centrifuged prior mr-said warsame nur MLS-

 Blood sampling through too
small bore of a needle
 Forced suction of blood in
the syringe during blood
collection
 Vigorous shaking of blood
from the syringe, especially
through a needle
 Centrifuging blood sample
at a high speed before clotting
 Freezing and thawing of
blood
 Unclean tubes with
residual detergents


 Serological reactions
detect either a specific
antigen produced by
the microorganism or a
specific immune
response of the human
body. Serological tests
may detect:

 Rapid identification of
agent
 High specificity of
detection of antigen
 Simplicity of
performance
 Safe procedures
 Diagnostic aids
 Epidemiological
tools
 Retrospective
confirmation of
diagnosis mr-said warsame nur MLS-

 Source
 Some control sera are available commercially. Small volumes are
generally available as components in kits but are intended to be
used only with a single kit. A few may be available in larger
quantities.
 Preparation
 Sera to be used as controls should be kept sterile to avoid
deterioration. In general each procedure should have a normal
control serum (negative), a strong positive control serum, and
another positive control serum which is reactive at the critical
concentration (borderline positive). With some tests, controls with
a low concentration of analyze should be included. Controls
recommended by the manufacturer of a particular test should
always be used and additional control sera can be included if a
test involves special problems.

 Sera to be used as controls
should be standardized
against international
reference materials when
they are available.
"Standards" included in
commercial kits are not
calibrated with each other
and often are not
interchangeable. These
should be stored in
aliquotes in frozen forms.
Repeated freezing and thawing
should be avoided. mr-said warsame nur MLS-

 Quality reagents are
necessary for quality
performance. A record
should be kept of any
changes in reagents in case
the performance of a test
changes. Before new
reagents are introduced
into a system they should
be tested in parallel with
the old reagents against a
panel of appropriate
reference sera to be sure
that consistent reactions
are obtained. The results
obtained with the panel
should reflect the sensitivitymr-said warsame nur MLS-

 Reagents should
be clearly labeled
to indicate their
identity, hazards
involved in their
use,
recommended
storage
conditions, and
preparation and
expiration dates.

 All glassware used in immunologic tests must be clean
and free of detergent. Chipped or etched glassware should
be discarded. Calibrated glassware should be checked for
accuracy.
 The user’s accuracy and precision requirements should be
met or exceeded when equipment is tested under working
conditions. The manufacturer’s specifications for
performance should be checked and met. Instruments and
equipment should be monitored routinely. The
temperature of water baths, incubators, refrigerators, and
freezers should be checked periodically and records
maintained. Maintenance should be pearformed and
records kept on a regular basis by individuals who are
trained and are familiar with the equipment.

 Instruments used
for
measurements
including
spectro-
photometers,
spectrometers,
dilutors, and
automatic
pipettes should
be calibrated on

Lecture 11-qualitycontrolinserology-110711110534-phpapp01

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Lecture 11-qualitycontrolinserology-110711110534-phpapp01