variant 1 bacid haemolysis

Question 1

Questions concerning the acid haemolysis of RBC
1. The aim of the study (5)

Answer 1

To compare the acid haemolysis resistance and the age distribution of RBC from
different individuals

Question 2

List the factors which can provoke haemolysis and describe how the process is carried out
experimentally (7)

Answer 2

Mechanical: Ultrasound, filtration through pores
ii. Thermal: increase in temperature
iii. Radiation: ionizing radiation
iv. Chemical: acid(hcl)
v. Biological: products of microorganisms,diff blood types, snake venom

It is examined experimentally using fragility (resistance) tests. These are divided into
two classes static and dynamic.
* in the static class the most widely used is the osmotic fragility test, where RBC are
exposed to media with decreasing osmotic pressures.
* In the dynamic class HCL is used as a haemolytic agent and the absorbance is
measured

Question 3

Describe shortly the experimental work and measurements performed in this practice. Show
as a graph a differential erythrogram and explain how the age distribution of red blood cells is
obtained- the percentage of young, middle aged and old erythrocytes (10)

Answer 3

RBC suspension is prepared with constant concentration
ii. Induction of haemolysis – mixing of 1.5ml suspension with 1.5 haemolytic
agent (HCL)
iii. Absorbance is read out every 30 seconds until haemolysis is finished
iv. Procedure is repeated twice until haemolysis is finished, absorbance values
are averaged, nonlinear regression of the data is performed

Question 4

continuation

Age distribution

Draw graph from answer

Answer 4

i. Partial haemolysis is calculated H [%] =100(TriAi/TriA)

ii. TriAi=Ai-Ai+30s

iii. TriA=A30s-Aend

iv. The H is plotted as a function of time in a graph for each studied sample

v. Age distribution determined by counting the number of 30s intervals for haemolysis to be complete

vi. Divide the obtained number with 3, summing H values for 1st 1/3 (old RBC), next 1/3 (medium old RBC) and last 1/3 (young RBC)

vii. Make comparisons between the parameters of the haemolytic process of the
blood samples studied

Question 5

Which parameter is used for comparison of the acidic resistance of different blood samples.
Give examples of disease, which can be screened with such type of tests (3)

Answer 5

The time for 50% haemolysis is used for comparison of the acidic resistance of
different blood samples
* Haemolytic anaemia can be screened with this test as resistance of RBC is decreased

Question 6

Write the first Fick law for free diffusion of a solute. Explain the parameters involved (8)

Answer 6

J=-D dc/dx

Question 7

Represent schematically the Stern model for the double electric layer of flat surface with
negative charge (9)

Answer 7

look in answers

Question 8

Write in the boxes the transport processes which contributes to the different flux
components in the following systems of equations (4)

Answer 8

the of solvent: filtration and osmosis

the of solute: filtration and diffusion

Question 9

Plot the dependence of the diffusion potential on the concentration gradient (5)

Look in answers

Answer 9

plot the lg c1-c2 and El

Question 10

Calculate the numerical value of the slope (a) for the Henderson’s equation using the results
in the table (5)

Answer 10

look in answers for the previous graph

Question 11

Calculate the paarmeter

Answer 11

0.0005v