The collection and submission of samples for laboratory testing.

The laboratory analysis of samples can be a valuable adjunct to the investigation of outbreaks of disease and to the identification and correction of production inefficiency. However, the costs associated with laboratory analysis are high; consequently, a decision to involve laboratory analysis as part of an investigation should be made judiciously. The purpose for the sampling should be directed and, in general, restricted to tests whose results can lead to a management decision. When dealing with complex and difficult problems, there is a tendency to buy decision time by taking samples for laboratory testing with the philosophy of "let's see what the laboratory can come up with." Undirected sampling seldom yields results that can be interpreted meaningfully to resolve the problem at hand.