A fluorometer for measuring a particular fluorescence emanating from a specimen and operating in accordance with the following method. Producing a burst of concentrated light energy and directing the concentrated light energy toward the specimen to produce a fluorescence from the specimen including the particular fluorescence. Preferably producing an image of the fluorescence. Detecting the fluorescence and producing a signal in accordance with the fluorescence. Controlling the passage of the image of the fluorescence for detecting within a particular time period so as to optimize the detection of the particular fluorescence. Timing the operation to sequence the detection of the fluorescence within the particular time period after the production of the burst of concentrated light energy. Scanning the fluorescence from the specimen for forming signals representative of the fluorescence from the specimen. Analyzing the signals to enhance the portion of the signal representing the particular fluorescence relative to the portion of the signal.