(M) Week 9: Screening test for unstable hemoglobin

Question 1

Which screening test is this for unstable hemoglobin:

The red blood cell hemolysate prepared from a blood specimen suspected with unstable
hemoglobin is incubated with 15% or 17% isopropanol and incubated at 37 OC

Answer 1

isopropanol precipitation test

Question 2

what percent of isopropanol is utilized in the isopropanol precipitation test

Answer 2

15-17%

Question 3

what do we check for in the mixture after 5 mins and 10 mins in the isopropanol precipitation test

Answer 3

precipitation / flocculation

Question 4

unstable hgb shows a (faster/slower) rate of precipitation

Answer 4

faster

Question 5

For isopropanol precipitation test

why do unstable hemoglobin precipitate faster?

Answer 5

their bonds are easily weakened by isopropanol

Question 6

normal hemoglobin start to precipitate at _______ minutes during the isopropanol precipitation test

Answer 6

45 minutes

40

Question 7

Which screening test is this for unstable hemoglobin:

The hemolysate prepared mixed with tris buffer solution with a pH of 7.4 is incubated at 50 deg C
for 2 hours and another duplicate sample is incubated at refrigerated temperature

Answer 7

heat denaturation test

Question 8

in heat denaturation test, unstable hemoglobin will precipitate easily at (high/low) temperature

Answer 8

high

Question 9

what is used to measure the absorbance of hemoglobin concentration of the supernatant of both the heated and refrigerated mixture using the cyanmethemoglobin method

Answer 9

spectrophotometric analysis

Question 10

what is the formula for the concentration of unstable Hgb

Answer 10

%unstable Hgb = (absorbance of refrigerated - absorbance of heated / absorbance of refrigerated) 100

Question 11

what are used to confirm the high level of unstable Hgb test in heat denaturation test

Answer 11

isopropanol precipitation test

Question 12

RBC with unstable hgb will form _______ after the cells are incubated with acetylphenylhydrazine

Answer 12

heinz inclusion bodies

Question 13

What is the stain used for the Heinz bodies inclusion test

Answer 13

crystal violet

Question 14

G6PD DEFICIENCY

red cells with faulty reducing systems will show more than _____ of red cells with 5 or more inclusions

Answer 14

32%

Question 15

G6PD DEFICIENCY

normal red cells will show less than ___ of red cells with 5 or more inclusions

Answer 15

32%

Question 16

Heinz bodies are common in these enzymopathies:

Answer 16

G-6-PD deficiency
glutathione peroxidase dificiency
triophosphate isomerase deficiency

Question 17

Where is the presence of Hgb H observed?

Answer 17

alpha-thalassemia major

Question 18

a condition where three alpha genes are absent or deleted caused by the excessive production of the beta globin chain in the cytoplasm of the red cells

Answer 18

alpha-thalassemia major

Question 19

what is the cause of alpha-thalassemia major

Answer 19

excessive production of the beta globin chain

Question 20

why is hemolytic anemia observed in alpha-thalassemia major?

Answer 20

excessive beta-globin chain => disfigured red cells => rapid removal by macrophages

Question 21

How do we increase the yield of positive detection of Hgb H in cases where patient is suspected with homozygous alpha thalassemia?

Answer 21

blood is incubated with 1% brilliant cresyl blue (oxidizing agent)

Question 22

what color would the Hgb H / excessive beta globin chains be in microscopic analysis?

Answer 22

multiple, evenly distributed bluish green colored bodies

Question 23

what pattern is observed in red cells in the microscopic determination in the Hgb H preparation and staining?

Answer 23

golf ball pattern

Question 24

reticulocyte inclusions are also stained by brilliant cresyl blue but shows what color

Answer 24

blue to purple