Serum Glucose

Question 0

Reference range

Answer 0

Serum, plasma (fasting) = 70-100 mg/dL or 3.9-5.6 mmol/L

Question 1

It reacts under catalysis of peroxidase with phenol and 4-aminophenazone

Answer 1

Hydrogen peroxide

Question 2

Reaction principle

Answer 2

Glucose + oxygen + water (GOD) —> gluconic acid + hydrogen peroxide

2 hydrogen peroxide + 4-aminophenazone + phenol (POD) —> quinoneimine + 4 water

Question 4

Stability of glucose if serum or plasma is prepared within 30 minutes after collection

Answer 4

24 hours at 2-8 Celsius

Question 5

Specimen

Answer 5

Serum

Question 7

Wavelength

Answer 7

500 nm, Hg 546 nm

Question 8

Optical path

Answer 8

1 cm

Question 9

Indicator

Answer 9

Red-violet quinoneimine dye

Question 10

The test is not influenced by

Answer 10

1 Uric acid
2 Ascorbic acid
3 Glutathione
4 Anticoagulants
5 Bilirubin
6 Creatinine

Question 11

Normal value of glucose

Answer 11

< 200 mg/dL

Question 12

Calculation of glucose concentration (mg/dL)

Answer 12

C = 100 x Absorbance (sample)/ Absorbance (standard)

Question 13

The glucose is determined after ________ in the presence of _______

Answer 13

Enzymatic oxidation

Glucose oxidase

Question 14

Linearity

Answer 14

The test is linear up to a glucose concentration of 400 mg/dL or 22.2 mmol/L

Question 15

Temperature

Answer 15

20-25 Celsius or 37 Celsius

Question 15

Incubation period

Answer 15

10 minutes (20-25 Celsius)
5 minutes (37 Celsius)

Question 16

Calculation of the glucose concentration (mmol/L)

Answer 16

C = 5.55 Absorbance (sample)/Absorbance (standard)

Question 17

Reagents

Answer 17

Phosphate buffer (pH 7.5)
4-aminophenazone
Phenol
Glucose oxidase
Peroxidase
Mutarotase
Stabilizers

Question 17

Reagent stability

Answer 17

Up to expiry date if unopened (2-8 Celsius)
6 weeks if opened (2-8 Celsius)
2 weeks if opened (15-25 Celsius)