B. Report Generation

Reports should be in a format that is readable and easily

understood, with appropriate references or explanations

as needed. They should be generated in a timely manner

relative to preanalytical and analytical components.

518 Concise Book of Medical Laboratory Technology: Methods and Interpretations C. Report Delivery

Report delivery should be timely, to the correct client, and

in a manner agreed upon by the client and the laboratory.

D. Specimen Storage

Specimens should be stored under appropriate conditions

for a predetermined time period, as determined by

specimen stability, laboratory policy and/or certification/

accreditation requirements.

E. Specimen Disposal

Laboratories should appropriately dispose of biohazardous

and non-biohazardous materials and specimens,

including timely emptying of all containers and trash bins.

F. Personnel Safety

Conditions should be appropriate for computer entry,

transcription, handling of specimens, specimen disposal

and all other postanalytical tasks.

G. Laboratory Environment

Laboratory environment should meet standard requirements necessary for safe, rapid, efficient and effective

performance.

H. Personnel Requirements

Personnel should meet training requirements as indicated

for specific areas of the laboratory.

20

Enzymology

C H A P T E R

For most enzymic estimations, special care has to be

taken regarding storage specifications of reagents/

kits. During testing one has to be extremely cautious

about temperature (incubation), pH, time settings, etc.

otherwise reproducible results may not be obtained. All

precautions listed in this chapter or those mentioned by

manufacturers should be cautiously followed to every

minutest detail.

ALPHA-AMYLASE

Serum and Urine—α Amylase

(Direct Substrate Method)

(Courtesy: Tulip Group of Companies)

For the determination of α amylase activity in serum,

plasma or urine (for in vitro diagnostic use only).

Summary

α amylase is secreted by the pancreas into the duodenum

where it aids the catabolism of carbohydrates to simple

sugars. Damage to the pancreas or obstruction to the

pancreatic duct causes the enzyme to enter the bloodstream. Elevated levels are found in acute pancreatitis,

perforated/penetrating peptic ulcers, parotitis (mumps).

Patients with chronic pancreatic disorders having

pancreatic cell destruction do not have high levels as less

amylase is produced by the pancreas.

Principle

α Amylase catalyzes the hydrolysis of a 2-chloro-4

nitrophenol salt to chloronitrophenol (CNP). The rate

of hydrolysis is measured as an increase in absorbance

due to the formation of chloro nitrophenol which is

proportional to the α Amylase activity in the sample.

 α Amylase CNP - Gal - G2 + H2O CNP + Gal - G2

Normal Reference Values

Serum : Up to 90 U/L at 37°C

Urine : Up to 490 U/L at 37°C

It is recommended that each laboratory establish its

own normal range representing its patient population.

Contents 2 × 10 mL 2 × 30 mL

L1: Amylase reagent 2 × 10 mL 2 × 30 mL

Storage/stability

Contents are stable at 2–8°C till the expiry mentioned on

the label.

Reagent Preparation3

Reagents are ready to use. Do not pipette with mouth.

Sample Material

Serum, heparinized plasma, urine.

α Amylase is reported to be stable in the sample for 5 days

at 2–8°C. Separate serum from clot as soon as possible.

Procedure

Wavelength/filter : 405/(Hg 405)/violet

Temperature : 37°C

Light path : 1 cm

For serum as sample:

Pipette into a clean dry test tube labeled as Test (T):

Addition

Sequence

(T)

37°C

Amylase reagent (L1) 1.0 mL

Sample 0.02 mL

520 Concise Book of Medical Laboratory Technology: Methods and Interpretations

Mix well and read the initial absorbance A0 after

1 minute and repeat the absorbance reading after every 1,

2, and 3 minutes. Calculate the mean absorbance change

per minute (∆A/min).