provided are methods , kits and arrays for carrying out relative measurement of an analyte of interest in a biological sample . as specifically exemplified , there is an array of stabilized , desiccated cdna preparations , each at a defined location within the array , where those cdnas were prepared from cells treated with a particular condition believed to modulate at least one gene of interest . detection can be via real time polymerase chain reaction using an appropriate reaction mixture and primers specific for a coding sequence of interest , and a greater relative amount of a rt pcr product from a control preparation reflects greater gene expression in response to the test condition whereas a lower amount of rt pcr product reflects an inhibitory effect on expression of the coding sequence of interest as a result of the application of the test condition .