Gel filtration media are very stable because of their ineptness towards biopolymers. In the experimental laboratory, gel filtration is reliable and simple, little equipment is required, the procedures are straightforward and good separations and yields are usually obtained. Several years ago, I began experimenting with a number of gels to determine the feasibility of designing high school laboratory experiences using gel filtration. I have successfully completed and utilized a number of these labs in my classroom. Sephadex beads are porous.
Smaller molecules enter the beads and are retarded based on their size.
Therefore, molecules are eluted in order of decreasing size. Sephadex G-25 excludes all molecules with a molecular weight greater than 5000, thereby eluting them first. A maximum of twenty four students in grades 9-12 of average to high ability can be targeted for each class instruction period. Forty-five minutes to one hour should be scheduled as operating time, depending on prior preparation. Two beakers Wire test tube holder.