Key Words: Egg white, albumen, solute exclusion, vital dye, methylene blue, gel-sol
Received 10 May 2010; revised 22 July; accepted 24 July. Published 19 August 2010; available online 19 August 2010
As reported here hen egg white can be separated by sieve filtration into thin and thick albumen fractions that remain as separate non-miscible fractions. Thick albumen but not thin albumen behaves as a gel and was found to have vital dye excluding properties. Thick albumen also demonstrates swelling and shrinking under osmotic conditions and the ability to transform from a dye excluding gel to a non-dye excluding more fluid sol under the influence of pressure or agitation. Thick albumen gel that had been agitated to a sol state was observed to transform from the non-dye-excluding sol state back to a dye excluding gel state when allowed to rest without agitation. These findings may help explain vital dye exclusion by most but not all cells.