OFT

Question 1

Disadvantages of OFT

Answer 1

1. Time consuming
2. Lack sensitivity
3. non-specific

Question 2

Main factor of OFT

Answer 2

shape of erythrocyte

Question 3

Shape of the erythrocyte depends on?

Answer 3

1. volume
2. surface area
3. functional state of erythrocytic membrane

Question 4

Whole blood + varying conc of NaCl

Answer 4

OFT

Question 5

Solution where water molecules will pass in & out of the membrane in EQUAL AMOUNTS

Answer 5

Isotonic solution

Question 6

What will happen to erythrocytes in HYPOTONIC solution?

Answer 6

1. RBCs will hemolyze;

2. more water molecules enter THAN leave

Question 7

It ruptures more quickly

Answer 7

Spherocytic erythrocyte

Question 8

Characteristics of spherocytic rbcs (dec or inc/ easily lysed or not)

Answer 8

1. easily lysed
2. ↓ SA:V
3. ↑ OFT

Question 9

Have large surface area per volume

Answer 9

Target/sickle cells

Question 10

Cells that can withstand osmotic pressure

Answer 10

Target/sickle cells

Question 11

Is erythrocytic fragility inversely proportional to the rate of hemolysis or directly?

Answer 11

Directly proportional

Question 12

Specimen used in OFT?

Answer 12

Heparinized Whole Blood/Fresh Defribinated Whole Blood

Question 13

How many hours is the specimen in OFT stable at room temperature?

Answer 13

2

Question 14

Stability hours of the specimen if refrigerated?

Answer 14

6

Question 15

T/F: In each tube water enters & leaves RBC until equilibrium is reached

Answer 15

TRUE

Question 16

1. Absorbance 0
2. Supernatant at tube 1
3. 0% hemolysis

Answer 16

Spectrophotometer digital

Question 17

1. percentage transmittance %T

2. conversion table to read absorbance

Answer 17

Spectrophotometer conventional

Question 18

Point where the tube with the highest concentration of NaCl

Answer 18

End point

Question 19

Concentration where hemolysis should end

Answer 19

0.30% NaCl

Question 20

T/F: Beginning hemolysis should NOT occur in a concentration >0.45%

Answer 20

TRUE

Question 21

Test wherein you will know the type of cells that are easily ruptured

Answer 21

Osmotic Fragility Test

Question 22

Initial & complete hemolysis of NORMAL OFT

Answer 22

I: 0.45%
C: 0.30%

Question 23

Initial & complete hemolysis of HEREDITARY SPHEROCYTOSIS

Answer 23

I: 0.65&
C: 0.45%

Question 24

T/F: Thalassemia & Sickle Cell Anemia DOES NOT have the same initial & complete hemolysis

Answer 24

FALSE; both have 0.35% (I) & 0.20% (C)

Question 25

↑ OFT

Answer 25

Hereditary Spherocytosis

Acquired Hemolytic Anemia w/ Spherocytes

Question 26

↓ OFT

Answer 26

Anemia w/ target cells

Question 27

Curve shifted to the right

Answer 27

RBC ↓ OF

Initial hemolysis of NaCl = >0.5%

Question 28

Curve shifted to the left

Answer 28

RBC ↑ OF

Question 29

Incubating blood in 37C for 24hrs before OFT

Answer 29

Incubated OFT

Question 30

It allows hereditary spherocytosis in a spherical shape

Answer 30

Incubated OFT

Question 31

Test that demonstrates ↑ RBC fragility & RBCs have ↓ surface-area-tp-volume ratios

Answer 31

OFT