A simple net search found: http://omrf.ouhsc.edu/~frank/hv_data.html http://www.stratagene.com/vol12_2/p49-51.htm -Peter "fisher" <foolio_j88 at yahoo.com> wrote in message news:%KW5a.1377$XR3.40892 at news.itd.umich.edu... > What's the difference between these two?? > >