Random hexamer mix includes oligonucleotides representing all possible hexamer sequences. Random hexamers are commonly used for priming singlestranded DNA or RNA for extension by DNA polymerase or Reverse transcriptase, typically when the template is difficult to copy in its entirely. During cDNA synthesis, random hexamer will random priming throughout the entire length of the RNA to generate a cDNA pool containing various lengths of cDNA. With this method, all RNAs present in a population constitute templates for the cDNA synthesis experiment.