Methods for heat-assisted enzyme digestion

A kit for protein sample preparation, the kit comprising:

• a solid support surface with a polymer coating covering the solid support surface, wherein the polymer coating comprises a first coating portion with functionality for bioconjugation and a second coating portion comprising a diol obtained from hydrolysis of an epoxide containing silane selected from the group consisting of a 3-glycidopropyl trifunctional silane and a 2-(3,4-epoxycyclohexyl) ethyl trifunctional silane, wherein the second coating portion renders the surface hydrophilic and reduces non-specific binding between a protein sample and the solid support surface, wherein the polymer coating is present at a total surface coverage of at least 5 μmoles/m2;
• a container containing a buffer solution;
• and
• a vessel for containing the solid support surface and the buffer solution, wherein the buffer solution comprises:
• 5% to 10% acetonitrile;
• from about 10 mM to about 20 mM arginine;
• from about 100 mM to about 300 mM methionine;
• from about 50 mM to about 200 mM Tris-HCl;
• from about 10 mM to about 20 mM CaCl2);
• and
• a polyol selected from the group consisting of xylitol, erythritol, glycerol, propylene glycol, and butanediol.