Suppose we have g itesm classified as defective or as nondefective. If we test each item separately, then g tests are required. However, it is possible to test a group of g items so as to detect whether at least one of them is defective, and to proceed to individual testing only if the presense of at least one defective item is indicated. The method is called Dorfman procedure. In this paper, we consider a variant of Dorfman procedure called a hierarchal dorfman procedure. We also consider the curtailment effect resulted from the dependency of the tests. We propose an efficient blood testing procedure. We also present ot heuristic rule of thumb which is simple and easily implementable.