A universal density gradient medium
Polysucrose 400 is a synthetic high molecular weight polymer made by the copolymerization of sucrose and epichlorohydrin. The molecules have a branched structure with a high content of hydroxyl groups giving a good solubility in aqueous solutions.
The reactivity and stability of Polysucrose 400 are determined by its hydroxyl groups and the glycosidic bonds in the sucrose residues. Polysucrose is stable in alkaline and neutral solutions. At pH values lower than 3, it is rapidly hydrolysed, especially at elevated temperatures. In neutral solutions, Polysucrose 400 can be sterilized by autoclaving at 100°C for 30 minutes without any degradation.
Polysucrose 400 is readily soluble in aqueous solutions when added slowly to the liquid with constant stirring. Concentrations up to 50% (w/v) can easily be obtained.
Using sodium metrizoate and a polysaccharide Bøyum (1968) developed a one-step centrifugal tech-nique for isolation of lymphocytes (Lymphoprep). In this method the polysaccharide aggregates the erythrocytes, thereby increasing their sedimentation rate. Polysucrose 400 has also been used as a den-sity gradient medium for the purification of other cells and in membrane fractionation.
Non-ionic high molecular weight solutes such as Polysucrose are required for a number of other research scenarios. Polysucrose 400 may be used as a stabilizing agent in protein solutions and it can function as an immuno-logically inert carrier for low molecular weight haptens in immunological studies. Polysucrose 400 is also used to reduce non-specific binding of labelled probes to nitrocellulose membranes during nucleic acid hybridization. It also simplifies the loading of nucleic acids into the sample wells of agarose gels for electrophoresis.
White odourless powder
|Specific optical rotation (α)D20||53° – 59°|
|Intrinsic viscosity (20 °C)||0.14 – 0.20|
|Average molecular weight (Mw)||450,000 ± 100,000 g/mol|
|Mw distribution by GPC||conforms to standard|
|Loss on drying (%)||< 5.0 %|
|pH (10 % w/v aqueous solution)||7.0 – 9.0|
|Sulphated ash||< 0.3 %|
|Content of chloride (ppm)||< 500 ppm|
|Microbiological contamination||< 100 CFU/g
<10 yeasts and mould/g
|Bacterial endotoxins||< 10.0 IU/g|
in the following package sizes:
|Prod. No. 7828||1 x 20 kg|
Bøyum, A. (1968)
Separation of leucocytes from blood and bone marrow Scand. J. Clin. Lab. Invest., 21, suppl.97