No sample preparation is required for free SO2 and glucose methods. Simply apply a drop of red or white wine to the test strip when prompted by the Sentia Analyzer. Malic acid, fructose and acetic acid methods require a simple pre-dilution with a specific diluent.  Wine samples undergoing titratable acidity should be degassed before analysis. See https://www.universalbiosensors.com/products/sentia/resources/ for further information.