Help with haemolysis in blood questions

[mareehf]

Hello,

I am new to this forum so hopefully I have not doubled up this question - I did search for it. Anyhow, can anyone help with the below questions?

Q1: Can haemolysis occur if erythrocytes are suspended in iso-osmotic solutions?
This question relates to Urea haemolysis times using 0.28M urea and 1.0M urea. 0.28M urea is iso-osmotic with isotonic solutions.
I know iso-osmotic solition is where 2 solutions have equal osmolarity. So I would answer no to this question, but I want to make sure as both the 0.28M and the 1.0M urea solutions haemolysed.

Q2: Why do cells not haemolyse in all solutions which are hypotonic?
This question relates to concentrations of NaCl and water solutions.

Thanks, appreciate anyones help.
Cheers

[JackBean]

A1: since it is isotonic, the cells should not break, at least not due to water flow. However, as you use urea, it could denature proteins leading to membrane rupture. However, I'm not sure, whether 0.28M urea would denature proteins

A2: what about the cell types? (the plant vs. animal cells;)