**2.1 Chemicals and reagents**

Sodium dodecyl sulfate (SDS), Trypsin, Sodium chloride (NaCl), Phosphatebuffered saline (PBS), Ethylene diaminetetraacetic acid (EDTA), Sodium azide (NaN3), Gentamicin, Potassium bromide (KBr) powder. All the chemicals and reagents used were of the high purity and obtained from Sigma-Aldrich (St. Louis, MO, USA) unless mentioned otherwise. All solutions were prepared fresh using deionized water and analytical grade chemicals at room temperature (unless indicated otherwise).
