What is the hyperchromic effect? How is it measured? What \(\operatorname{does} T_{m}\) imply?

Answer: The hyperchromic effect is the increase in absorbance of UV light by a DNA molecule upon denaturation (or melting), as the unwinding of the double helix into individual strands allows more UV light to be absorbed. It can be measured using a spectrophotometer, by recording the absorbance of a DNA sample over a range of temperatures until the melting temperature (Tm) is determined. Tm, the temperature at which half of the DNA molecules are denatured, is significant for determining the stability of a DNA molecule and predicting optimal temperatures for hybridization and annealing in techniques like PCR and DNA microarrays. Higher Tm values imply higher DNA stability, while lower Tm values indicate lower stability or weaker DNA duplexes.