Abstract: Described herein are methods and systems for analyzing and visualizing HRM data from a double-stranded nucleic acid. The HRM data is generally characterized by a plurality of data points each including a signal value associated with the concentration of a double-stranded nucleic acid in a sample and a temperature value associated with a the temperature of the sample. Embodiments of the invention analyze the HRM curves from samples using the first negative derivative of the HRM curve or a virtual standard. The first negative derivative plot method may be used to identify the melting temperature of a homogenous double-stranded nucleic acid in a sample, as well as the presence and melting temperature of heterogeneous double-stranded nucleic acids in the sample. Data points associated with the melting temperature are plotted on a scatter plot for analysis. The virtual standard allows for visualization of HRM data across data sets.