Hi, if it is a column that you can open and repack I think you should take out the Protein A resin and add some buffer or 20%ethanol, gently stir to mix, leave it for about 1 h to reswell and repack the column.

If you can't open the column you may be able to fix it by slowly pumping a lot of buffer through it, but perhaps the packing will not be perfect.

Regarding the binding capacity I have seen some decrease when the resin has been dried out for a longer time, but often you are able to use the resin again when it is reswollen.

Anna Heijbel is right. You can reuse it, and you can expect somewhat decreased performance.

Also, I would run your stripping buffer and re-equilibrate before trying to load again, especially if you cannot repack.

Drying a protein A resin column can potentially damage the resin and affect its performance. However, there might be a chance to recover it depending on the extent of the damage. Here are some steps you can try to potentially recover your dried protein A resin column:

Rehydration: Slowly and gently rehydrate the dried resin by adding the appropriate buffer (usually a binding buffer or an equilibration buffer) to the column. Allow the resin to soak in the buffer for some time to regain its original hydrated state. This process might take several hours to overnight.

Stirring and Mixing: After rehydration, gently stir or mix the resin slurry to help break up any aggregates or clumps that might have formed during the drying process.

Equilibration: Once the resin is rehydrated, wash the column with the appropriate buffers as you would during a normal equilibration process. This will help remove any contaminants and excess buffer from the resin.

Quality Control: After rehydration and equilibration, perform a quality control check to assess the resin's binding capacity, efficiency, and overall performance. You can do this by running a small-scale purification or binding test with a known protein sample to see how well the resin performs compared to its original state.

Regeneration: If the resin's performance is compromised even after rehydration and equilibration, you might need to consider regenerating or recharging the resin according to the manufacturer's instructions. Regeneration steps may involve using specific reagents to remove contaminants or to rejuvenate the resin's binding capacity.