Molecular Weight Determination of β -Lactoglobulin by Membrane Osmometor
Chuanhuan Luo, Rongqing Huang, Bingkun Xiao, Qiande Liang, Xiaodong Liang (Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850)
Difference concentration solutions of β -Lactoglobulin were injected into upper half of measurement cell in membrane Osmometer. The lower half of cell was full of saline with a semi-permeable membrane laying a middle of cell. NaCl molecular in upper cell permeated to lower cell through semi-permeable membrane so that pressure to the pressure measuring membrane in bottom of lower cell was formed. As a result, an electrical signal was produced. After amplication, this signal was led to a recorder. Osmon pressure л was read on recorder. the (п/c) can be found on п/c-c drawing. Molecular weight of β-Lactoglobulin was about 17000 and its double association, about 35000 from caculating vant’ Hoff formular (R=848, T=0K, C=concentration of sample, п=osmotic pressure, D=specific gravity of solvent).