<prompt> Which of the following techniques is used for detection of variation in DNA sequence and Gene expression?Nohern blotSouthern blotWestern blotMicroarray  <response>: DNA microarray also commonly known as DNA chip or biochip is a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome. 