Retest: SC256 Diffusion with a Mixture of BSA and DDM
On Friday I posted results from a diffusion experiment in which I tested “treated” and “untreated” SC256 samples against the diffusion of a mixture of DDM and BSA. The DDM-BSA solution contained an initial DDM concentration of 1.0% and an initial BSA concentration of 2.5mg/mL; the solution also contained 20mM HEPES and was at a pH of 7.5 (no salt was present). The analysis from that experiment showed that DDM was passing through both the “treated” and “untreated” SC256. BSA was detected in the filtrate collected from both samples but it appeared that it was at a lower concentration in the “treated” case. I set up another diffusion experiment to verify this result and allowed it to run over the weekend.
BSA Analysis:
It appears that BSA diffuses across both the “treated” and “untreated” SC256 samples. Similarly to the results posted on Friday the concentration of BSA calculated in the “treated” filtrate is lower then that of the “untreated” filtrate. The final concentration of the “untreated” filtrate was calculated to be ~0.21mg/mL and the final concentration of the “treated” filtrate was calculated to be ~0.11mg/mL.
DDM Analysis:
In both the “treated” and “untreated” SC256 samples similar amounts of DDM diffused across the membrane. The final concentration of DDM in the “untreated” filtrate was ~0.09% and the final concentration of DDM in the “treated” filtrate was ~0.08%.
Today I plan on setting up another similar diffusion experiment introducing 10mM salts into solution. If you recall from our meeting on Tuesday with Professor Dumont a lot of their work is done in the range of 1mM to 100mM salts.