• high buffer capacity and solubility at pI = well-defined separation
• good even conductivity = no burn through
• linear pH runs = even protein distribution
• low molecular weight = fast fixing, staining and destaining
Sepalyte consists of polyamines with an average of six nitrogen atoms. The polyamine is substituted with derivatives of sulfonic and carboxylic acids at varying concentrations. Free primary and secondary amino groups provide an ideal buffer system over a wide pH range. The average molecular weight is between 400 and 700 dalton, components higher than 1000 dalton have been eliminated. For some pH ranges spacers and fillers are added in order to linearize and spread the pH gradient where necessary for an improved performance.
Properties and Storage
Sepalyte appears as a syrupy, non-hazardous, aqueous liquid, having 40% of solids. The standard types are filtered sterile through 0.2 µm filters. A solution in water of 1 g per 100 ml (based on dry weight) has an 0.D. of 0.1 at 280 nm. Below 280 nm light absorption increases abruptly. Sepalyte is a good nutrient medium for many microorganisms and should therefore always be kept in the refrigerator. Stocks of Sepalyte, especially if already opened, should be stored in the freezer at –20°C. Some fractions become turbid during storage in the cold. However, upon dilution the turbidity disappears.