Abstract: This invention relates to a kit and to a method of using the kit for the in situ detection of trace quantities of drugs on any surface. The method involves using a sampling means that is purposefully designed to sample trace elements of a drug to sample an unknown drug, chemically reacting the sampled drug with a buffer or digesting solution to produce a composition which is detectable, by immunological techniques. To test the reacted sample it is placed in a well in a detection tablet that has been impregnated with a detecting chemical and produce a visible indication of the presence of absence of a particular drug.