Question

Can you please calculate the lysed
1. Fill in the table of the relevant results below and calculate the percentage of lysed RBC assuming that 0% salt solution gives 100% lysis. (3 marks) Tube Number [NaClj (%) Absorbance at 540 nm % Erythrocytes Lysed 30 3 40 50 0.178 0.182 0.187 0.211 0.183 0.052 0.021 60 80 100

Answer 1

A suitable NaCl concentration is required for the maintenance of RBC integrity, as we know that RBC behave differently in different solutions as an optimum NaCl concentration required for maintening isotonic condition which is 0.9% and below this concentration is hypotonic and higher the 0.9% is a hypertonic concentration in cell which shrink. If we keep RBC in 0% NaCl which is serous hypotonic condition in which cell will burst and cell lysis will take place.

Here, in the given problem 100% cell lysis is present tube1 where no NaCl used.

Tube	% of NaCl (from 1% buffer)	OD at 540nm	(Difference from 0% NaCl)	% lysis
1	0	0.178	0	100
2	30	0.182	0.004	97.75280899	(calculated through 0% NaCl, final substracted from 100)
3	40	0.187	0.009	95.05494505	(calculated through 0% NaCl, finally substracted from 100)
4	50	0.211	0.033	77.40788623	(calculated through 0% NaCl, finally substracted from 100)
5	60	0.183	0.005	97.63033175	Note: error in the absorbance, due to pipetting
6	80	0.052	-0.126	0	error/negative values, near to physiological conc
7	100	0.021	-0.157	0	(as physiological conc is 0.9% which is close to 1% NaCl, so no lysis may be seen in this concentration)
formula used=	100-{(OD difference/0.178)*100}