General: Particle Sizes and Pore Diameters
The selection of the particle size distribution and pore diameter for your application varies on the type of chromatography being done. In addition, not all the 40-63um gels are the same, i.e the absence of so-called fines (particles below 40um) has a great impact on performance.
Typical pore sizes used for purification of different molecules depend on their molecular weight.
For small organic molecules with molecular weights Mw < 1.000 the typical pore sizes is 60 and 70A, for Mw < 400 40A. For peptides with Mw < 10.000 pore sizes 90-300A are applied and for polypeptides and bio-polymers with Mw > 10.000 typically pore sizes of 1.000A are applied.
The most popular particle size application and distributions are described hereafter.
5 - 20 µm
- Contain neither binder (organic or inorganic) nor UV indicator (F254)
- Can also be used in flash chromatography if higher resolution is required (higher back-pressure)
- Specialized Particles for Difficult Separations: 15 - 35 µm
15 - 40 µm
- High-resolution silica for difficult separations (similar polarities)
- Particles for Flash Chromatography
40 - 63 µm
- Chromatography types: high-resolution flash chromatography & low to medium-pressure preparative chromatography
- Narrow particle size over other flash chromatography silica
- Easier to pack
- More uniform packing
- Superior resolution
- Suitable for uses with complex matrices
60 - 120 µm
- Alternative to 40-63 µm silica gel for faster flow rate without pressure
- Particles for column (or Gravity) Chromatography 60 - 200 µm
- Most economical silica for open column chromatography (gravity)
- Suitable for rough purification and large-scale preparative chromatography
- Easier to handle
- Purification cost reduction
120 - 200 µm
- Silica for standard open column chromatography
- Narrow particle size enables uniform packing
- Suitable for mass overload purification