A method is provided for identifying viral positive biological fluid donations in the fewest number of test cycles. The method comprises providing biological fluid donations and defining an n-dimensional matrix comprising a multiplicity of elements, each element being identified by a matrix notation comprising an index for each dimension of the array. Samples are taken from each fluid donation and mapped to a matrix element with each sample identified by its corresponding element's notation; n aliquots being taken from each sample and subpools formed from the aliquots with each subpool containing an aliquot from all samples mapped to elements in which one of the dimensional indices is fixed. Subpools are tested for viral indication and the dimensional index of each subpool that returns a positive viral indication is determined. The dimensional indices are combined to identify a subset of matrix elements that contain a viral positive sample.