Class IV G6PD enzymes include which of the following? a. ...

[jenna1]

Class IV G6PD enzymes include which of the following?
 
  a. G6PD-Mediterranean
  b. G6PD-B and G6PD-A+
  c. G6PD-Iowa
  d. G6PD-Canton

Question 2

What are the principles of the following tests?
 
  a. Fluorescent spot test
  b. Dye reduction test
  c. Ascorbate cyanide test
  d. Rate reduction test
 
  What will be an ideal response?

[sultansheikh]

Answer to Question 1

Correct Answer: B

Answer to Question 2

Answer: Fluorescent spot test: Whole blood is added to a mixture of G6P, NADP, and saponin. G6PD enzyme metabolizes G6P and produces NADPH (which fluoresces). NADP does not. Lack of fluorescence indicates G6PD deficiency.
Dye reduction test: similar to fluorescent spot test except for indicator: blue color to colorless  presence of G6PD; blue color remains  absence of G6PD
Ascorbate cyanide test: nonspecific test. Tests the ability of RBC catalase to inhibit hydrogen peroxide formation. G6PD-deficient patients allow hydrogen peroxide to form, which promotes the formation of methemoglobin. The presence of methemoglobin turns the solution brown.
Rate reduction test: Measures rate of conversion of NADP to NADPH via spectrophotometry at 340 nm.