With more education and experience, accountants can become certified. Some financial documents, such as those submitted to the Securities and Exchange Commission, must be signed by a Certified Public Accountant.
Hyperchromicity is the increase of absorbance (optical density) of a material. The most famous example is the hyperchromicity of DNA that occurs when the DNA duplex is denatured. The UV absorption is increased when the two single DNA strands are being separated, either by heat or by addition of denaturant or by increasing the pH level.
At the core of the PCR method is the use of a suitable DNA polymerase able to withstand the high temperatures of >90 Â°C (194 Â°F) required for separation of the two DNA strands in the DNA double helix after each replication cycle.