Disclosed are controls for use in identifying any of a number of genotypes and/or for use in identifying or characterizing a disease or condition. The controls may be particularly useful for diagnostic tests that utilize circulating cell-free DNA or microRNA. A control may comprise a mixture of nucleic acids. In some embodiments, a control comprises liposomes, e.g., wherein nucleic acids of the control are associated with the liposomes. For example, the controls are useful for determining whether a fetus comprises an aneuploidy. Also disclosed are methods of using the controls.