Two microvolume nucleic acid quantitation protocols will be demonstrated using NanoDrop Products that employ integrated sample retention systems. First, a direct A260 absorbance method using a NanoDrop 2000c microvolume spectrophotometer is described. This is followed by a demonstration of a fluorescence-based method that enables reduced-volume fluorescence reactions with a NanoDrop 3300 microvolume fluorospectrometer. These novel techniques enable the assessment of nucleic acid concentrations ranging from 1 pg/ μL to 15,000 ng/ μL with minimal consumption of sample.