A Modification of the Method for Prestaining Alpha and Beta Lipoproteins Separated by Paper Electrophoresis

HEN ONE EMPLOYS the classic method for staining lipoproteins after separation by paper electrophoresis (3, 4) one encounters difficulties in attempting to evaluate the alpha and beta bands. These problems are manifested in: 1. detection of alpha lipoprotein present, 2. problems of elution, and 3. the inability to scan strips on a photoelectric scanner. The disadvantage in using postelectropho-retic staining is that it not only stains the lipid bands, but also results in a high color background to all of the paper strip. Because of these inadequacies we decided to develop a prestaining technique that would clearly stain only the lipid material but would not affect the background color of the ifiter paper. EQUIPMENT AND REAGENTS 1. Petroleum ether-alcohol solvent. Mix 1 part of reagent grade petroleum ether with 4 parts of absolute ethyl alcohol. 2. Saturated solution of Sudan Black “B ” (certified stain) pre-pared in the above solvent. 3. Barbiturate buffer, pH 8.6, ionic strength 0.05. 1.85 Gm. barbital (diethylbarbituric acid) and 10.30 Gm. of sodium barbital are dis-solved in water and diluted to one liter in a volumetric flask. The buffer may be purchased preweighed as Spinco No. 300-811 buffe