This versatile, multi-function HPLC autosampler can access samples from microtiter plates and standard autosampler vials, accommodating 96 and 384 standard and deep-well microplates, or up to 48 standard sample vials in a supplied rack. Sample cooling is available on selected models. Biocompatible fluidics are standard with optional stainless steel plumbing. The Model 540 incorporates three selectable injection modes: full loop, partial loopfill and microliter pick-up. Sample processing capabilities are provided for sample mixing, dilution and on-line sample derivatization. An optional plate feeder can fully automate sampling from as many as seven standard plates and three deep-well plates. An optional Peltier sample temperature control is also available for cooling of sample vial/plates.