Reference Library-Technical Note

Gradient Materials

Primarily the choice of gradient materials depends on the product and impurity in the gradient. Once stability and density are determined, then the material giving the greatest separation can be used.

Commonly used ionic matrices are alkali metals, i.e. Caesium chloride (CsCl), potassium tartrate and potassium bromide, which create high densities with low viscosity although they are all corrosive. CsCl is frequently used for process development as a high degree of purity can be achieved due to the wide density gradient that can be created (1.0 to 1.9 g/cm³).

Potassium bromide can be used at high densities, but only at elevated temperatures, i.e. 25° C, which may be incompatible with stability of some proteins.

Sucrose is widely used due to being inexpensive, non-toxic and can form a gradient suitable for separation of most proteins, sub-cellular fractions and whole cells. Typically the maximum density is 1.3 g/cm³. The osmotic potential of sucrose maybe toxic to cells in which case complex gradient material may be used e.g. Nycodenz®.

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Technical Notes

AlfaSIP™ - Sanitization by Pure Chlorine Dioxide

Custom Installation

Gradient Materials

Linear Scale-up Rotors for KII & PKII Ultracentrifuges

Protocol Development Technology on the AW Promatix 1000™

The Reorienting Gradient Technique

Single Step Clarification, Concentration and Purification

Application Notes

K Series Rotors for KII Production Scale Ultracentrifuges

PK Series Rotors for PKII Pilot Scale Ultracentrifuges

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