Gas chromatography-mass spectrometry is generally used to identify drug forensic evidence. However, depending on the drug sample being used for analysis, Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy are sometimes used in a forensic analyst's determination of the drug's chemical compound.
Trace analysis is used in a forensic lab to determine where trace evidence such as hair, fingernails, gun shot residue and fibers came from in a crime scene. An example of how chemistry is used in trace analysis would be when determining if a suspect fired a weapon. The back of the suspect's hands are swabbed with dilute nitric acid and then chemically analyzed in the lab for gun shot residue.
Forensic labs use serology, the study of bodily fluids, to make various determinations in a crime scene. Fluids generally used are blood, saliva and semen. These substances are tested biochemically through techniques such as immunoelectrophoresis, isoelectric focusing and enzyme-linked immunosorbent assay.