Acetonitrile (ACN, 100%, HPLC-grade) AssayMAP Labware (AM200) Centrifuge (capable of 50 - 1000 x g) and deep microplate rotor with clearance of minimum 44 mm height Formic acid (HPLC-grade) Heater and incubation blocks, capable of 50–100°C, available from Agilent (GS150) Ultrapure, deionized water