Method and apparatus for generating thermal melting curves in a microfluidic device

A method of determining the thermal inertia of a microfluidic device, the method comprising:

• flowing a fluid comprising a fluorescent material through a channel in a microfluidic device, wherein the amount of fluorescence generated by the fluorescent material varies with temperature,
• varying the temperature of an external surface of the microfluidic device, wherein the variation comprises a pattern with a recognizable feature, wherein the variation in temperature of the external surface produces a corresponding variation in temperature within the channel, and wherein the variation in temperature in the channel produces a corresponding variation in the amount of fluorescence generated by the fluorescent material,
• measuring the fluorescence generated by the fluorescent material in the channel, and
• determining a time offset between the temperature variations of the external surface and the variations in the amount of fluorescence by measuring the time delay between the imposition of the recognizable feature on the external surface and the appearance of the recognizable feature in the fluorescence generated by the fluorescent material, whereby the time offset is indicative of the thermal inertia.