Haemolysis Lab Report

Results The objectives of this experiment were to investigate diffusion of molecules across a membrane and the factors that affect the rate of diffusion. The hemolysis time of sheep erythrocytes was measured for each of eight different nonelectrolyte solutions by eleven groups in BI 108 Section D2. These eight nonelectrolytes were urea, thiourea, methanol, ethanol, propanol, ethylene glycol, diethylene glycol, and triethylene glycol, and the mean hemolysis times can be seen below in Figure 1. The mean hemolysis time for urea was 11.90 seconds (±2.65 sec, n = 11). Thiourea took an average of 92.72 seconds (±12.41 sec, n = 11) to hemolyze 75% of erythrocytes, while methanol took 9.19 seconds (± 1.66 sec, n = 11). The black line was seen through
The mean hemolysis times of sheep erythrocytes in 0.3 M urea, thiourea, methanol, ethanol, propanol, ethylene glycol, diethylene glycol, and triethylene glycol were calculated, and paired, two-tailed t-tests were conducted to determine statistical significance. It was found that the difference in hemolysis time between methanol and ethanol was not statistically significant (P = 0.0666, t = 2.0577, df = 10); the same result was found between the results of ethanol and propanol (P = 0.0888, t = 1.8851, df = 10). The difference between hemolysis time for methanol and propanol, however, was found to be statistically significant (P < 0.05, t = 2.0577, df = 10), as was the difference between urea and ethylene glycol hemolysis time (P < 0.001, t = 20.9104, df = 10). The results were expected to show statistically insignificant differences between ethanol, methanol, and propanol. On the other hand, urea was expected to diffuse significantly faster than ethylene glycol (Hunter 1976). The hypothesis regarding hemolysis time was that the lipid/water partition coefficient would be directly correlated with speed of hemolysis, while molar volume would be indirectly correlated (Gardner and Godrick 2011). Therefore, increased molar volume would increase the hemolysis time and increased lipid/water partition coefficient would decrease the hemolysis
Firstly, it is possible to use sheep erythrocytes as models for human erythrocyte behavior because permeability similarity increases for more closely related species (Hunter 1976). Using an even more closely related species’ erythrocytes in diffusion experiments would provide an even better model for human cell behavior. Additionally, finding out more about diffusion mechanisms may allow scientists to synthesize compounds that have specific desired diffusion characteristics. This will allow better targeting of drugs, which would have a great impact on medicine for a variety of disorders.

Works Cited
1. BI 108 Section D2. 2011. Principles of Biology II. Biology Department, Boston University, Boston, MA.
2. Gardner KE and Godrick EC (eds). 2011. Principles of Biology II. Hayden-McNeil, LLC, Plymouth Michigan. Module # 3, pp 41-64.
3. GraphPad. 2009. t test calculator. Website: http://www.graphpad.com/quickcalcs/ttest.cfm. Accessed Feb 14, 2011.
4. Hunter, F. R. "Permeability of Trout Erythrocytes to Nonelectrolyes." Biological Bulletin 151.2 (1976): 322-30.