CHOLESTEROL DETERMINATION

Question 1

In the principle of the test of cholesterol determination, what does cholesterol esterase do?

Answer 1

It hydrolyzes esters to free cholesterol and fatty acids.

Question 2

After the free cholesterol is produced, the cholesterol oxidase will ______ it to form products ________ and _______

Answer 2

OXIDIZED; Cholest-4-en-3-en-one and Hydrogen Peroxide (H2O2)

Question 3

What is produced when phenol is oxidatively coupled with 4-aminophenazone?

Answer 3

A quinoneimine chromo gene / Quinoneimine dye

Question 4

To form a quinoneimine dye, what is the enzyme and substrate needed besides the color developers?

Answer 4

Enzyme: POD - Peroxidase, Substrate: H2O2

Question 5

What is the secondary reaction for cholesterol determination?

Answer 5

Cholesterol + O2 –COD–> Cholest-4-en-3-en-one + H2O2

Question 6

What is the tertiary reaction for cholesterol determination?

Answer 6

H2O2 + 4-aminophenazone + Phenol –POD–> O-quinoneimine dye + H2O

Question 7

What is the color of the end product quinoneimine dye and its’ absorption maxima?

Answer 7

Red ; 500 nm

Question 8

The blood sample should be collected following how many hours of fasting?

Answer 8

12

Question 9

The anticoagulant for sample collection is?

Answer 9

EDTA

Question 10

What should be avoided when collecting samples for cholesterol detrmination?

Answer 10

Hemolysis - as it can interfere with the result.

Question 11

In specimen stability of cholesterol determination, at what temperature should the samples be kept?

Answer 11

2-8C / 35.6F-46.4F

Question 12

The specimen stability should be kept for how many days?

Answer 12

4 days

Question 13

In extended stability, the total cholesterol should be kept for how many days, and at what temperature?

Answer 13

3 months for -20C/-4F

Question 14

In extended stability, the HDL should be kept for how many days, and at what temperature?

Answer 14

7-14 days at -20C/-4F

Question 15

What are the two interfering substances that could result to false low values?

Answer 15

Sodium fluoride and oxalate

Question 16

What is the standard for hemoglobin and bilirubin to avoid interfering the test?

Answer 16

Hemoglobin: 200 mg/dL, bilirubin: 10 md/dL

Question 17

Enumerate the manual procedure for cholesterol determination.

Answer 17

1. Pipette 1.0 mL (1000uL) of reagent in 3 tubes (S, U, RB)
2. Incubate for 37C/99F/310.15K all cuvets for 5 minutes.
3. Add 10 uL (0.01ml) of sample and reagent
4. Incubate all cuvettes at 37c for 5 minutes.
5. Read S and U vs RB at 500 NM for 60 MINUTES.

Question 18

The cholesterol reagent should be stored at what temperature?

Answer 18

2-8C/35.6F-46.4F

Question 19

Before using the cholesterol reagent, keep it aat room temperature which converted as?

Answer 19

22C/71.6F/273.15K

Question 20

Once reagent is opened, the consumption of the product should last for?

Answer 20

1 week

Question 21

What is the cholesterol standard?

Answer 21

200 mg/dL

Question 22

What is the normal result for newborn?

Answer 22

53-135 mg/dL

Question 23

What is the normal result for infant?

Answer 23

70-175 mg/dL

Question 24

What is the normal result for children?

Answer 24

120-200 mg/dL

Question 25

What is the normal result for adolescent?

Answer 25

120-210 mg/dL

Question 26

What is the normal result for adult?

Answer 26

140-310 mg/dl

Question 27

What is the desirable result for adults?

Answer 27

140-200 mg/dL

Question 28

What is the equation for serum cholesterol?

Answer 28

Au/As x 200

Question 29

What is the molecular formula of phenol?

Answer 29

C6H5OH

Question 30

What is the molecular formula of 4-aminophenazone?

Answer 30

C13H17N3O