On Recovery of Sparse Signals in Compressed DNA Microarrays

Currently, DNA micro arrays comprising tens of thousands of probe spots are employed to test entire genomes in a single experiment. Typically, each microarray spot contains a large number of copies of a single probe, and hence collects only a single data point. This is a wasteful use of the sensing resources in comparative DNA microarray experiments, where a test sample is measured relative to a reference sample. Since only a small fraction of the total number of genes represented by the two samples is differentially expressed, a large fraction of a microarray does not provide any useful information. To this end, in this paper we consider an alternative microarray design wherein each spot is a composite of several different probes, and the total number of spots is potentially much smaller than the number of genes being tested. Fewer spots directly translates to significantly lower costs due to cheaper array manufacturing, simpler image acquisition and processing, and smaller amount of genomic material needed for experiments. To recover signals from compressed microarray measurements, we leverage ideas from compressive sampling. Experimental verification of the proposed methodology is presented.