These terms are not very precise, but it can be said that mild acid is a buffer with pH in the range 4-6, for instance acetate buffer. Mild basic is a buffer in the range from 7.5 to 9, for instance a carbonate/bicarbonate buffer or Tris base. Concentration depends on your requirements and nature of the protein sample,  but usually 0.05 to 0.1 are uaed. I hope this can help you.

These terms are not very precise, but it can be said that mild acid is a buffer with pH in the range 4-6, for instance acetate buffer. Mild basic is a buffer in the range from 7.5 to 9, for instance a carbonate/bicarbonate buffer or Tris base. Concentration depends on your requirements and nature of the protein sample,  but usually 0.05 to 0.1 are uaed. I hope this can help you.

Thanks Solano sir for this information.

My purpose was solved by using 0.1 M Acetic acid.