Hi Juan, I am not sure the volume you have but you could dialize the sample in a large volume of the new buffer, or use a spin concentrator to reduce the volume of the current buffer, bring up to initial volume in the new buffer, spin concentrate again (repeat as needed to get needed ratio of new buffer to old). Usually two rounds will get you to 99% new buffer, depends on initial volume and volume retained in the spin concentrator.

Hope this helps.

Frank

Hi there,

You might run a SEC experiment on a system equilibrated with the given buffer.

How to change the buffer of a protein solution?

Your Buffer is PBS 1X (8 g of NaCl, 0.2 g of KCl, 1.44 g of Na2HPO4, 0.24 g of KH2PO4, adjust the pH to 7.4 with HCl and add distilled water to 1 liter.

Firstly, I have a question: what buffer and what component do you want to change. Yet do you want to change the pH or/and the ionic strength or and the buffer chemicals.

Secondly, since you have a lyophilized membrane protein, so you should take in mind its solubility and its activity in the new buffer. Maybe, you could solubilize a little amount of your protein in a selected buffer and test its activity and also its stability in the new buffer.

However, a rapid method to change buffer is to solubilize your protein in the selected new buffer and maybe do a dialysis in that buffer.

Good success

You said your membrane protein is in PBS buffer. What detergent does your PBS buffer have?

An alternative to dialysis, if you know the size of your protein, you can use a centricon that has pores smaller than the size of your protein (if protein size is 100kDa, the you should use a centricon with pore size of 30kDa or 10kDa). Then you put the sample in X buffer in the centricon and dilute it with the new buffer, you centrifuge and your sample will be in the new buffer. You migh need add more of the new buffer and centrifuge several times to make sure your sample is completely in the new buffer.

Keep in mind that your new buffer also need to have the detergent you are using or the new detergent you want to use.

Good luck with your protein