Random k-set pool designs are known to be efficient but suffer the presence of clones having identical test sets (hence indistinguishable). We propose a random pool design with distinct k-sets. We give an algorithm to generate the design and compute the expected numbers of unresolved negatives and unresolved positives. We show a relation between the two numbers which holds also for other random designs; hence, it can be used to obtain their expected numbers of unresolved positives which are not known. Among these other random designs, the random size-k design is a new design.