Before developing a new liquid class, consider using predefined liquid classes as starting points, as they may already be close to your desired definition. In some cases, you may be able to use existing liquid classes without any changes. Most instrument manufacturers have predefined liquid classes for the following categories: aqueous solutions, biological fluids/blood, viscous liquids, volatile organic solvents, and nonvolatile organic solvents.
For example, to create a new liquid class for your PCR master mix, you can begin with water. However, there may be definitions that are even closer to your needs. If you are using an extraction kit, contact the manufacturer to see whether they have predefined liquid classes or something similar. A binding buffer based on a high molar concentration of Guanidine Thiocyanate, for example, will share similar properties with another binding buffer of a similar composition. Reference the manufacturer's Safety Data Sheets (SDS) to find a comparable liquid class definition.
(Typically Dense/Viscous Aqueous Solution)
||Volatile Organic Solvents
||Nonvolatile Organic Solvents
|Buffered Solutions (i.e. TE/PBS)
||Higher Alkanes (i.e., mineral oil)
|Most Enzymatic Reaction Components
Identify a predefined liquid class from this table to start with. It has been arranged to classify groups of liquids that affect liquid handling similarly. Properties that most affect liquid handling include vapor pressure, viscosity, surface tension adhesion, cohesion, density, and capillary action.