Urine toxicology testing (i.e., urinalysis) includes chemical analysis of an individual's urine to assist in determining the presence of mind-altering substances. In most cases, the urine sample is sent to a testing agency for analysis. However, panel dip tests are also available that permit the person who obtains the urine sample to conduct immediate on-site analysis, leading to immediate feedback of urine toxicology results. Although the results of many of the older dip tests were open to interpretation, most of these tests now permit a positive or negative reading for each drug tested (i.e., positive indicates the drug-produced metabolite was present). When objective substantiation is important (e.g., legal proceedings), the urine specimen can be sent to a testing agency for analysis through thin layer chromatography ...