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2. If the tourniquet has been applied for long, it should be removed and blood
allowed to circulate for at least 2 minutes before the blood is withdrawn.
3. Collect 2 ml of blood in a container with EDTA as anticoagulant.
HTAA, KUANTAN C) Specimen Transportation

1. Chilled the specimen in ice slurry and send immediately to the laboratory.
Specimen received not in chilled condition will be rejected.

Notes:
Specimen for ammonia measurement must be centrifugated within 15 minutes of
collection to obtain the plasma. Delay in separation will cause elevation of ammonia
due to the generation and release of ammonia from the red blood cells. Once
separated, plasma is stable for 2 hours at 2 - 8 C and 3 weeks at -20 C.
o
o
4.3 Oral Glucose Tolerance Test (OGTT)

A) Preparation before Specimen Collection

1. The patient should be on unrestricted diet (containing at least 150 g of
carbohydrate per day for three days ) and activity.
2. Patient should fast overnight (at least 8 hours but not longer than 16 hours).
Plain water is allowed but no other beverage is permitted.

B) Procedure of Collection

1. In the morning following the overnight fast, take basal blood specimen for
glucose determination. Labelled the specimen as Glucose (FBS). Complete the
request form including the test requested (OGTT: FBS) and time of sampling.
2. Give 75 g glucose in 250-350 ml water (For children, the glucose dose is 1.75
g/kg body weight up to a maximum of 75 gm). Patient should finish the drink
within 5 minutes.
3. Take further blood specimen at 2nd hour after glucose load. Labelled the
specimen as Glucose (2HPP). Complete the request form including the test
requested (OGTT: Glucose (2HPP)) and time of sampling.

Notes:
Patient should rest throughout the test; smoking not permitted; drinks of plain water
are allowed.

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