Alkaline Phosphatase

Question 0

Reaction principle

Answer 0

p-Nitrophenylphosphate + water – (AP) – phosphate + p-nitrophenol

Question 1

Method

Answer 1

Liquicolor, Colorimetric test

Question 2

Contents

Answer 2

1 Reagent 1/Buffer solution: Diethanolamine buffer (pH 9.8)

2 Reagent 2/Substrate solution: p-Nitrophenylphosphate

Question 3

Specimen

Answer 3

1 Serum

2 Heparinized plasma

Question 4

Loss of activity within 7 days at 4 Celsius

Answer 4

0%

Question 5

Loss of activity at 20-25 Celsius

Answer 5

10%

Question 6

Procedure 1 with reagent start

Answer 6

The reagents are stable, even after opening, up to the stated expiry date when stored at 2-8 Celsius. Contamination of the reagents must be avoided.

Question 7

Procedure 2 with sample start

Answer 7

The working reagent is stable for 4 weeks at 2-8 Celsius and for 5 days at 15-25 Celsius

Question 8

Wavelength

Answer 8

Hg 405 nm (400-420 nm)

Question 9

Optical path

Answer 9

1 cm

Question 10

Temperature

Answer 10

1 25 Celsius
2 30 Celsius
3 37 Celsius

Question 11

T or F. Read against air (increasing absorbance)

Answer 11

T

Question 12

Procedure with sample start

Answer 12

Mix sample and reagent mixture, read the absorbance after 1 minute and at the same time, start the stop watch. Read the absorbance again exactly after 1, 2, and 3 minutes.

Question 13

Linearity

Answer 13

If the absorbance change per minute exceeds 0.250, dilute 0.1 mL of the sample with 0.5 mL physiological saline (0.9%) and repeat the assay using this solution. Multiply the result by 6.

Question 14

Calculation

Answer 14

1 Method 1 with reagent start
U/l = mean absorbance per minute x 3433
2 Method 2 with sample start
U/l = mean absorbance per minute x 2757

Question 15

Conversion factor

Answer 15

(Review)

Question 16

Reference range

Answer 16

(Review)

Question 17

Contain sodium azide as preservative

Answer 17

1 Buffer solution (R1)

2 Substrate solution (R2)

Question 18

Produced during the reaction

Answer 18

p-nitrophenol