Anne ImObersteg has analyzed over 20,000 blood and urine samples for alcohol content, over 10,000 biological specimens for drugs, and about 2,000 drugs in solid form (bindles/baggies etc.).

The type of testing procedure used depends on the type of sample involved. In general, the testing procedure involves the extraction of the drug from the biological matrix, and analysis on analytical instruments. The choice of instruments used vary from laboratory to laboratory.

Regardless of the method used, the selected analytical method must provide accurate and reliable results. As with any instrument, the quality and worth of the data achieved though analytical analysis is a function of how the instrument is maintained and operated. Confirmation methods must be validated to ensure the reliable analysis of specimens. The instrument must be used in the proper manner as well. The calibrators that establish the quantitation of the result, and the controls that check the proper results of the calibrators, must be used in the analytical run and fall within acceptable ranges of accuracy.

Laboratory analysis of a biological sample is typically performed in two separate stages. The first analysis is generally called an “initial test”, “screening”, or “presumptive” test. Generally, the screening test is performend by an immunoassay testing kit. The screening test separates out negative specimens from specimens that may potentially be positive for a particular drug or drug class. A test result that is considered “negative” is generally not tested any further. "Positive" results are sent on for confirmation via a more specific instrument such as a Gas Chromatograph-Mass Spectrometer (GC/MS). This instrument allows drugs in the case sample to be identified by evaluating the actual molecular structure of the drug.

Drugs in their original form (powders and liquids) are also analyzed in two stages. The methods for analysis vary from laboratory to laboratory. Ideally, the sample is screened via a color or crystal test, and the results confirmed with an analytical instrument such as a GC/MS or FTIR. Most common for local criminalistics laboratories, is the use of color and crystal tests, since the tests are quick and inexpensive.