DNA Thermal Denaturation Lab

What Experiment Are We Running? As DNA is heated, heat breaks the hydrogen bonds holding base pairs together, unzipping the double helix into single strands. Single-stranded DNA absorbs significantly more UV light at 260 nm (A₂₆₀) than double-stranded DNA. By tracking absorbance across temperatures, you will map denaturation curves to discover each sample's melting temperature (Tm) and infer its G–C vs. A–T composition.
1

Select Unknown DNA Sample

2

Adjust Temp (°C) & Measure

Sample A
Temperature
50 °C
UV Absorbance
1.002
A₂₆₀ Reading
50°C 60°C 70°C 80°C 90°C 100°C
Show Experiment Visualizer
3

Recorded Experimental Data Tables

Sample A Data
Temp (°C) A₂₆₀ Action
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Sample B Data
Temp (°C) A₂₆₀ Action
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Sample C Data
Temp (°C) A₂₆₀ Action
No points recorded yet
Sample D Data
Temp (°C) A₂₆₀ Action
No points recorded yet
Lab Notebook Guide: Record data points across temperatures (50°C to 100°C) for each sample, then transcribe into your lab notebook to determine Tm values and write your CER justification.