MLAB 2401: Clinical Chemistry
Keri Brophy-Martinez
Automation
History of Automation
• 1957
– Technicon develops the first automated analyzer
• Continuous flow
• Issues: carryover and costly
• 1970
– Dr Anderson(NASA) develops a centrifugal analyzer
– DuPont ACA revolutionized chemistry with a non-continuous flow, discrete
analyzer with random access availability
• 1976-1978
– Kodak Ektachem: dry slide technology
• Small volumes of sample
• Reagents on slides for dry chemistry analysis
• 1980-Present
• Discrete analyzer take over Chemistry
• “walk-away” capabilities
Ektachem & ACA
• http://tiny.cc/n6pw2
Drivers For Technology Advances
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Reduction in TAT’s
Staff shortages
Economic factors
Increase throughput
Reduction in lab error
Increase safety
24/7 operations
Focus on automation of tasks rather than
manual methods
Automated Chemistry Analyzers
• Advantages
– Increased number of tests/technologist
• each tech can perform more tests during a period
of time
– Minimizes variations in results
• eliminates errors in pipetting, calculations
– Small sample size and reagent volumes
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Automated Chemistry Analyzers
• Disadvantages
– Methods vary with the instrument type, etc.
– Generally, cost of equipment, maintenance,
amount of QC
– Techs must be kept knowledgeable & careful in
set-up and operations
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Basic Types of Instruments
• Continuous flow
• Centrifugal analysis
• Discrete analysis
• Batch analyzer
– perform only test that is requested
– can perform many combinations of tests
– do not consume reagents for tests not ordered
– Continuous flow, centrifugal and discrete analyzers can all use batch
mode
Automated Chemistry Instruments
• Continuous flow analysis
– Reagents are pumped continuously through the system.
– Samples are introduced sequentially at timed intervals and follow each
other through the same network of tubing coils, heating baths and
photometer / other detector.
– While economical for profiles of tests, not good for stats or single
order tests.
– All samples get all tests, ordered or not
– Could not easily interrupt the process once initiated.
– *Also prone to “carryover”.
– Wasteful of reagents
– Example: Chem 1 By Technicon
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Automated Chemistry Instruments
• Centrifugal analysis
– A discrete system where the transfer of
solutions is carried out by the use of
centrifugal force
– Runs multiple samples, one test at a time
– Example:
• Cobas-Bio and IL Monarch
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Automated Chemistry Instruments
• Discrete analysis
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Each sample is contained in a
separate reaction vessel
 Make up the majority of modern
chemistry analyzers
 Run multiple tests one sample at
a time or multiple samples one
test at a time called RANDOM
sampling
 Examples:
 Dade Behring Dimension
RXL
 Kodak Ektachem
 Alfa Wasserman Ace Alera
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Automated Chemistry Systems
• Wet chemistry systems
– Reagents come ready to use or lyophilized and
must be reconstituted
– Systems include batch and profile analyzers or
stat analyzers
• Examples: Beckman Coulter CX-7, Vitros, Dade,
Advia, Roche Integra, Hitachi, Alfa Wasserman Ace
Aleria, etc.
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Automated Chemistry Systems
• Dry reagent systems
 Reagents can be tablets or found on cellulose
fibers located on strips, cards, or layered on
film.
 Reagents easy to handle, store well, and have
fairly long shelf life.
 Examples: Vitros, Seralyzer, Kodak Ektachem,
ChemPro, Dupont Analyst
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Automated Chemistry Analyzers
• Concepts and definitions
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Automated Chemistry: Terms
– Throughput
– Max # samples that can be processed in 1
hour
– Dwell time
– minimum amount of time required to get
test result after sampling
• varies greatly with instrument
• can be important consideration when selecting
instrument
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Automated Chemistry:Terms
• Stat testing
– Latin statum = immediate
– a widely used (abused) word in the lab, used to
prioritize work
– Stat turn around time - within 1 hour after order
entry
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Costing of chemistry lab tests
• Things that are included in pricing
– labor – processing
– equipment maintenance
– reagents - including a portion of start-up
– calibration and QC
– consumables - containers, paper
– capital - proportionate amt of life of instrument
– hospital overhead - facility maintenance
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Automated Chemistry
• Test repertoire
– What tests the instrument is capable of doing
• Consider cost analysis
– Immediate test repertoire
• What it can do without any changes (set- up or
programmed for)
– Total test repertoire
• Total number of tests that can be performed on the
instrument, with a few changes, ie. reagents, filters or
components.
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Analytic Phases
• Preanalytic
• Analytic
• Postanalytic
Preanalytic Phase
• Specimen collection
– Right tube for right tests
– Proper patient label
– Correct draw site
• Specimen transport
– Phlebotomists
– Volunteers
– Pneumatic-tube systems
Analytic Phase
• Sample handling
– Important to check the specimen for hemolysis,
lipemia, clots or fibrin
– Some analyzers use closed-tube,some open-tube
– Most instruments utilize a level-sensing probe to
detect the amount of serum or plasma in a tube
Summary of Analyzer Operations
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Sample identification: bar code or manual read
Determination of tests to be performed: LIS can communicate this
or operator
Reagent systems and delivery: reagents dispensed into cuvet
Specimen measurement and delivery: sample aliquot in
introduced into reaction cuvet
Chemical reaction phase: Sample and reagents mixed and
incubated
Measurement phase: Optical readings
Signal processing and data handling: Concentration is estimated
from a calibration curve stored in analyzer
Send results to LIS or read and entered off results tape
Postanalytical Phase
• Bidirectional communication
• Decreases opportunity for error
• Auto-verification
Trends
• Total Laboratory Automation (TLA)
– Integrated work cells
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Specimen manager
Track system
Immunoassay
Chemistry
References
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Bishop, M., Fody, E., & Schoeff, l. (2010). Clinical Chemistry: Techniques, principles, Correlations. Baltimore:
Wolters Kluwer Lippincott Williams & Wilkins
http://ashepages.com/productshowcase.php?ps_id=6574
http://www.asdiagnostics.co.uk/products/clinical-chemistry.php
http://www.clpmag.com/issues/articles/2008-02_02.asp
http://www.mann-horton.com/chem1.htm
http://websites.labx.com/rankin/detail.cfm?p=0&autonumber=1104
http://www.idsys.com/multitest-blood-analyzer/
http://www.idexx.com/view/xhtml/en_us/smallanimal/inhouse/vetlab/common/dry-slide-animation.html
http://www.southtexasblood.org/blood_general_facts.asp
Sunheimer, R., & Graves, L. (2010). Clinical Laboratory Chemistry. Upper Saddle River: Pearson .