The invention provides a method for reducing stutter in the amplification of a microsatellite comprising the steps of providing a sample comprising a microsatellite having a G+C content of 50% or less; contacting the sample with at least one enzyme having nucleic acid polymerase activity; and incubating the sample with the enzyme for a sufficient amount of time and under conditions sufficient to amplify the microsatellite; wherein the incubation is performed in the presence of an amount of betaine, sorbitol or mixtures thereof, effective to reduce stutter relative to the amount of stutter observed in the absence of betaine and/or sorbitol. The invention also provides compositions containing betaine and/or sorbitol, kits for amplifying microsatellites having a G+C content of 50% or less, and methods of using all of the foregoing.