DNA is susceptible to denaturing at high alkaline pH levels. Alkaline solutions with a pH 11 or greater are characterized by an abundance of hydroxide ions. These negatively-charged ions adversely affect the stability of the DNA double helix by removing hydrogen ions from the base pairs of DNA. This breaking of the hydrogen bonds between two oligonucleotides denatures the structure of the double-helix separating the DNA into its component strands.