The pa3 primers are designed with a sequence of 5???-paNNNNXXX-3???, where N is an equal mixture of A, C, G, and T, and each X is only one of A, C, G, and T such that each of the 64 different tubes has a different permutation of the XXX triplet. (The pa portion of the primer will include CTAG (corresponding to the GATC Mbo I site) immediately preceding NNNNXXX.) The pb3 primers are 5??? tagged wit