CoolLED has unveiled the pE-100 LED source for fluorescence microscopy applications. The company says that it is simple to fit and to use, delivers a long stable lifetime of ≥10,000 hours, requires no bulb changing or warm-up and involves no downtime. Because it contains no hazardous materials, there are no disposal issues. The user selects the appropriate wavelength and specifies the microscope model. Instant on/off and intensity control from 0 to 100% in 1% steps negate the need for either a shutter or neutral density filters.