Creatinine

Question 1

who described the method for the determination of creatinine involving a protein-free filtrate and reaction with picric acid in an alkaline solution.

Answer 1

Jaffe (1886)

Question 2

interferences of creatinine

Answer 2

protein and glucose

Question 3

Kinetic procedures have become popular because they are __, ___, ____

Answer 3

rapid
simple
avoid interference

Question 4

The present method is based on a modification of the automated reaction rate of ____ and _____.

Answer 4

Fabinay and Eringshausen

Question 5

Principle of Creatinine

Answer 5

Creatinine + Picric Acid —> Creatine-picrate complex

Question 6

reagent preparation

Answer 6

1 part of creatinine acid
! part of creatinine base

Question 7

working reagent is stable for ___ days, ___°C

Answer 7

30 days, 15-30°C

Question 8

Creatinine Acid Reagent =
Creatinine Base Reagent =
Creatinine Standard =

Answer 8

Aqueous solution of picric acid
Aqueous solution of sodium hydroxide
Aqueous solution of creatinine zinc chloride.

Question 9

sample stability

Answer 9

1 day = 2-8°C
months = -20°C

Question 10

preservation of urine

Answer 10

15 grams boric acid = 4-7 days RT (15-25°C)

Question 11

specimen used

Answer 11

Serum
urine: 24-hour urine (1:20 (1+19))

Question 12

wavelength used

Answer 12

510 nanometer

Question 13

reaction type

Answer 13

kinetic

Question 14

creatinine came from

Answer 14

kidneys, muscles

Question 15

Formula

Answer 15

serum: au/as x 5
Urine: au/as x 5x 20

Question 16

procedure

Answer 16

Manual Procedure
1. Set spectrophotometer cuvette temperature to 37°C.
2. Zero spectrophotometer with D.I. water at 510 nm.
3. Pipet 1.0 mL of working reagent into test tubes and prewarm at 37°C for 3 minutes.
4. Transfer 0.050 mL (50 µL) of standard to test tube, mix, and immediately place in cuvette well.
5. After exactly twenty (20) seconds read and record absorbance (A1).
6. At exactly sixty (60) seconds after reading (A1), read and record absorbance (A2).
7. Calculate the change in absorbance (∆A) by subtracting (A2-A1).

Question 17

Normal Range:

Answer 17

Male (serum): 0.9 - 1.5 mg/dL
Male (urine): 1000 - 2000 mg/24hrs.
Female (serum): 0.7 - 1.4 mg/dL
Female (urine): 600 - 1500 mg/24hrs.