Publisher Summary: This chapter discusses that in biochemical labeling studies, in enzymatic digestion, and in optical studies of the membrane, the residual hemoglobin may cause an unwanted problem. Methods that deplete the membranes of all cytosolic materials through multiple washing steps generally form membranes that cannot be resealed tightly again. To overcome these problems, the following gel filtration procedure was developed. After collecting the membranes, it has been found convenient to reverse the flow to clear the column of the released hemoglobin. This is the fastest approach, since the hemoglobin front is down only about one-third the length of the column. The column may be cleaned by reverse flow with two to three bed volumes of isotonic saline, pH 7.6. The agarose should recover its white color. About once a week, depending on the frequency of use, the column is rinsed with two bed volumes of solution F to control bacterial growth.