A DNA chip (also referred to as a DNA microarray) is an organized arrangement of DNA sequences on a solid surface in a 2-dimensional (2D) or 3D manner, either covalently or non-covalently bound to the surface. Arrays contain oligonucleotide probes or short nucleotide “known” sequences that can be used to hybridize to sequences in sample for various applications such as measuring the level of gene expression or identifying a particular mutation of interest.