The Combimatrix arrays are semiconductor-based oligonucleotide microarrays and are generated based on CombiMatrix technology (hyperlink) of in situ synthesis as outlined at www.combimatrix.com. The CustomArrayâ„¢ 4x2k is a microarray that is divided into 4 sectors, each of which can contain up to 2,240 different oligonucleotide probes (spots) and can be hybridized individually with different targets using a provided sectored hybridization cap.