Abstract: The present invention uses the small temperature changes from reactions and utilizes them in high throughput screening methods. Briefly, a thermal block containing a series of thermally isolated wells is used so that a reaction can take place in each well without affecting the temperature of any other well. A chemical or biological reaction, such as a binding reaction, is allowed to occur in each well or chamber and the optical properties of the all of the wells are monitored using optical, preferably Kromoscopic, measurements. A determination of temperature in each of the wells from those Kromoscopic measurements can be used to determine if reaction occurred.