NPN: Methods of Measurement

Question 1

Indirect enzymatic method for measurement of Urea. Best used as a kinetic measurement.

Uses GLDH and 2-oxoglutarate

Answer 1

GLDH-Coupled Reaction

Question 2

Two reactions used for indicator dye indirect enzymatic method to produce a color change

Answer 2

Nessler’s reaction and Berthelot reaction

Question 3

Explain Nessler’s reaction? What is used and what is produced?

Answer 3

NH3 + Nessler’s Reagent + Gum Ghatti –> yellow solution

Question 4

Explain Berthelot’s reaction

Answer 4

NH3 + Alkaline Hypochlorite + Na Nitroprusside –> Indophenol Blue

Question 5

Indirect enzymatic method used for conversion of unionized urea to and results in increased conductivity

Answer 5

Condumetric

Question 6

Proposed reference method for Urea

Answer 6

IDMS

Question 7

Direct enzymatic reaction that uses DAM / Diacetyl Monoxime that produces a yellow solution

Answer 7

Fearson’s reaction

Question 8

What is added in Fearson’s reaction to enhance color formation and eliminate protein interferences?

Answer 8

Arsenic thiosemicarbazide

Question 9

Chemical method for uric acid where allontoin is reduced to tungsten blue

Answer 9

Phosphotungstic Acid

Question 10

Enzymatic methods for uric acid determination

Answer 10

1. First Step –> uses uricase
2. Coupled enzyme –/ uses catalase, peroxidase
3. Spectrophotometric @293nm

Question 11

Specimen requirement for uric acid

Answer 11

Heparinized plasma, serum, or urine

Question 12

Creatinine is produced by?

Answer 12

Creatine and creatine phosphate, and three amino acids: arginine, methionine, and lysine.

Question 13

Considered the index of overall renal function

Answer 13

Creatinine

Question 14

Three diseases increased in hypouricemia

Answer 14

Fanconi’s, Wilson’s, and Hodgkin’s

Question 15

Folin Wu and Lloyd’s/Fuller’s difference in Jaffe Reaction

Answer 15

Folin-Wu is senstive. Lloyd’s/Fuller’s is sensitive and specific.

Question 16

Method used for automated determination of creatinine

Answer 16

Jaffe Kinetic

Question 17

Accepted reference method for creatinine

Answer 17

IDMS

Question 18

Two most common enzymatic reaction used for creatinine determination

Answer 18

1. Creatinine-H2O2
2. Creatinase-CK