This invention provides methods for characterizing the amounts of nucleic acids, including plus/minus determinations, the use of different constructs, the use of a library and a reference library. Expression may also be compared in two or more samples using the methods of this invention. Also provided are heterophasic arrays comprising labeled positive copies of nucleic acids hybridized to the array and labeled negative copies of nucleic acids hybridized to the array, in which the labeled positive copies are separately quantifiable from the labeled negative copies.