Chromatography Columns FAQ

1. We want short wide columns for our scale up. Radial flow Column look narrow and tall, wouldn’t the back pressure be high?
   Think of the Radial Flow Column as a short fat column that has been rolled like a donut. The flow now goes from the outside in as opposed to top down. Area is still large, bed height small and the foot print much smaller.
2. If the flow goes horizontally, can there be channeling in these columns?
   When properly packed, Superflo columns consistently outperform conventional columns as measured by HETP calculations.
3. Do I have to change my resins or my buffers in order to use these columns?
   No, the columns are designed to speed up your separation and reduce back pressure for all on/ off or frontal chromatography applications like Protein A, ion exchange, affinity, HIC, reverse and normal phase silica with the exception of size exclusion.
4. If I am cycling Protein A columns, how can Superflo columns help me?
   By reducing cycle times dramatically you can cut down the process times significantly. Also, if Protein A cost are a consideration, smaller radial flow columns can be used with more rapid cycles.
5. How are yields and recovery compared to conventional columns?
   Generally the recovery and purity should not be affected by the column geometry. In some cases superior recovery is achieved because the quick capture and elution of target protein minimizes the adverse effect of proteases. Non specific binding of undesirable components is minimized leading to increased purity.
6. How are the product volumes?
   Because of the highly efficient distribution in the Superflo Columns the elution volumes are lower, thereby reducing buffer requirements and downstream processing volumes.
7. Are Superflo Radial Flow Columns sanitary?
   Yes, the Radial Flow Columns are designed to be sanitary, drainable and ASME rated if desired. Large Superflo Columns are available in both Polymeric (Acrylic and Polypropylene) and 316 Stainless Steel. They use FDA approved materials and come with all necessary certification in a validation package.
8. How do I scale up from a small size, say 50 ml to large process size say 20L column volume?
   Sepragen supplies a Wedge Column which looks like a slice of the Radial Flow pie shaped column and has the same bed height and inlet/ outlet area ratio. Flow rates, sample size and buffer volumes can all be proportionately increased while the back pressure, resolution and separation time stays constant.
9. Do you have small columns for method development and viral challenge studies?
   Small 5- 10 ml wedges serve as methods development tools for viral inactivation studies.
10. How difficult are these columns to pack and unpack?
    The columns are very easy to pack. Packing and unpacking can be performed without disassembling the column. The slurry is pumped into a primed column through a slurry port located at the bottom of the column and the column is packed from the outside in until a given compaction is indicated by a pressure rise. The column is unpacked as slurry by simply pumping in buffer and opening the packing port.
11. Are there any limitations with Radial Flow Columns?
    Radial flow columns should not be used with size exclusion separations which require a large bed height. They may however be used as a guard or pre column for enrichment cuts. Also the columns are fixed volume columns.
12. How do Superflo Columns compare to other radial flow columns?
    Other columns experience “blow-by” or channeling before the main peak comes out which can lead to product loss or cross contamination.
13. Can Superflo Columns be used to capture proteins from unclarified feed stock?
    Yes, you can pack big bead resins in the column along with larger pore frits. Cell debris can thus flow through the column bed while the proteins are absorbed and eluted enabling both clarification and separation to be done in one step. See Superflo applications for details.
14. How do Superflo Radial Flow Columns compare with other alternatives like membrane absorbers or monoliths?
    Of the various commercial options available, Superflo columns are attractive because they combine the high throughput available with membrane absorbers with the high capacity of conventional columns. Unlike membranes and monoliths, they are scalable to very large volumes and like conventional columns they can be used with any proven resin chemistry. A comparison chart is shown below: