Liquid detection Sensor

Reagent warming Pre-heated ARM

Reagent identification Position ID

Tray exchange Possible with reagent bottles

Reaction

Number of wells 144 wells (12 wells × 12 strips)

Well volume 1 mL

Well temperature 37 ± 2°C

Diluter

Syringe 1000 µL, 1 µL steps

Accuracy ± 1% at 5 µL

Computer

Computer Built-in

Computer description Intel®

 Processor, 20 GB HD, 128

MB RAM

Operating system Microsoft Windows®

 display

TFT 12”, 800 × 600

Network adapter Built-in

Printer Built-in thermal printer, 120

mm

Output RS 232, LPT

Drive CD ROM, Floppy disk 3.5” 1.44

M bytes

General

Power Supply AC 115–230 V 50–60 Hz full

range

Dimensions 720 (W) × 680 (D) × 750 (H)

open or 530 (H) close mm

Weight 55 kg

PRINCIPLES OF QUALITY ASSURANCE AND

STANDARDS FOR CLINICAL CHEMISTRY

Preanalytical Factors Important in Clinical Chemistry

A. Specimen Collection, Handling, and

Transport to the Laboratory

Samples should be appropriately collected, handled

and transported to the laboratory in a timely manner,

dependent on the type of specimen and its stability.

For any assay performed in the laboratory, information

concerning sample requirements, proper collection,

handling, and delivery or shipping procedures should be

available to clients in a laboratory services manual, special

information sheets, journal or newsletter articles, other

written material, or by personal or telephone conversation.

B. Specimen Identification

Specimens should be identified with pertinent information

as determined by the laboratory, name of clinic or doctor,

address, telephone and fax numbers, e-mail address,

location from which the specimen was collected, etc.) on

the submission container and submission form.

C. Test Identification

The requested test(s) should be clearly stated on the

submission form.

D. Specimen Accessioning

The specimen should be correctly entered into the laboratory

system. Test request entry, delivery of the specimen to the

correct location, and specimen aliquoting (if necessary)

or sharing between laboratories or departments (i.e.

pharmacology, endocrinology, and clinical chemistry)

should be coordinated.

E. Client Communication and Education

Communication between laboratory personnel and clients

should be timely and courteous regarding preanalytical

factors influencing laboratory test results (e.g. incomplete

submission forms, inappropriate sample or sample handling

Clinical Chemistry 515

or poor sample quality). Clients should be informed of the

expected time for receipt of preliminary and final reports.

F. Personnel Safety

Personal protective equipment should be appropriate

for handling specimens and equipment used for clinical

chemistry. Safety procedures and disposal of all samples

and supplies should be appropriate for the type of

specimen. Personnel should receive safety and biohazard

training and information about exposure to potentially

hazardous chemicals or infectious agents. All training

should be documented.

G. Laboratory Environment

The laboratory space should be clean, well lit, and organized

to ensure proper achievement of the above goals.

H. Personnel Requirements

Laboratory personnel should have training in specimen

handling and sample preparation. Documentation of

training, continuing education and periodic proficiency

assessment should be at the discretion of the laboratory

director.

Analytical Factors Important in Clinical Chemistry

A. Monitoring

1. Internal monitoring should include the following

a. Quality of water (as specified by instrumentation and

essays)

b. Stability of electrical power (as specified by instrumentation)

c. Temperatures of water bath, refrigerator, and freezer

(recommended at least monthly)

d. Regular calibration of analytical balances and pipettes

(recommended annually)

e. Maintenance of up-to-date procedure manuals

with clearly stated dates when procedures are first

implemented and when any changes are made and

implemented

f. Maintenance of adequate inventory, with proper

storage and handling

g. Maintenance of a log of changes in any procedures,

problems or other factors affecting methods, as well

as actions that resolved the problem. All entries should

be clearly dated and signed by laboratory personnel.

2. External monitoring should include participation in

an external proficiency program

a. All participating laboratories should analyze the same

materials

b. Results should be tabulated regularly (monthly,

quarterly) and distributed to participants with

statistical summaries and comparison of participating

laboratories with mean indices expressing the

closeness of individual laboratory results to the group

mean

c. Means should be calculated and analyzed based

on identification of the method (same methods

compared)

d. Each laboratory should carefully assess the validity of

their reported performance and consider any changes

indicated by the proficiency program

B. Method Validation

Method validation should be performed before a test

procedure is placed into routine use. Validation may be

accomplished by thoroughly testing reference materials

or by comparison of results of tests performed by an

alternative method. For each method, the laboratory

should verify the manufacturer’s claims and any

adjustments before initiating patient testing.

Method validation should provide evidence of the

following:

1. Accuracy—Perform either (a) or (b)

 a. Run known value substance and compare results

to expected value

 b. Perform split sample patient comparison between

existing method of known accuracy and new

method.

2. Precision—Perform either (a) or (b)

 a. Run 10 replicates of 2 levels of quality control (QC)

samples

 b. Gather 21 results; 7 results in each of 3 separate

runs (better estimate of day-to-day precision, as

well as without-run precision).

With results from (a) or (b) determine mean, standard

deviation (SD) and coefficient of variation (CV). Determine

whether within-run SD is acceptable.

3. Sensitivity—Perform (a), (b) or (c)

 a. Assess manufacturer’s claims

 b. Use concentration of low calibrator or another

sample or fluid with low levels of analyte

 c. Run a series of dilutions and assess acceptability

of performance.

4. Specificity—Perform (a) or (b)

 a. Use published list of interfering substances, check

with manufacturer

 b. Assess known or suspected interfering substances

by spiking specimens or use patient material with

known conditions.

516 Concise Book of Medical Laboratory Technology: Methods and Interpretations 5. Linear reportable range

 a. Establish upper and lower limits for reporting

patient values based on calibration materials

 b. For the lower limit, there should be confirmation

of the discriminatory ability of the test

 c. The highest calibration point is the maximum

upper limit and the lowest calibration point or zero

should be the minimum lower limit for reporting

patient results.

6. Linearity—Perform either (a) or (b)

 a. Determine by analyzing multiple dilutions of either

a high calibrator, control or patient samples with

increased levels of analyte

 b. Analyze calibrators of variable, known concentrations

 c. Linearity should be established at the time of

validation and whenever new or altered reagents

are used.

7. Reference intervals

 a. The laboratory should establish or validate existing

reference intervals for each method and species

before reporting results

 b. Parallel tests should be run to confirm reference

intervals for controls when changing reagents or

QC lot number.

C. Instrumentation

1. Instrument performance

 The equipment and instrument used must be capable

of providing test results within the laboratory’s stated

performance characteristics. These include:

 a. Detection limits

 b. Precision

 c. Accuracy

 d. Specificity

 e. Sensitivity

 f. Freedom from interferences and related test

variables (refer to previous section on method

validation)