A variety of tests are available. In general, testing is most reliable from an independent laboratory that has also been certified by a 3rd party for accuracy and dependability. The most common test is for the determination of concentrations of various cannabinoids and terpenoids. This provides the dispensary and consumer important information as to the medical properties of the products. Genetic tests are also available which are helping to determine which genes result in plant phenotypes; this information may also be used in the development of new strains. Marijuana can also be screened for microorganisms, pesticides, and residual solvents; these factors help confirm the safety and purity of the product.