PCR can be used to determine sex from a human DNA sample.  The loci of Alu element insertion is selected, amplified and evaluated in terms of size of the fragment. The sex assay utilizes AluSTXa for the X chromosome , AluSTYa for the Y chromosome , or both AluSTXa and AluSTYa, to reduce the possibility of error to a negligible quantity. The inserted chromosome yields a large fragment when the homologous region is amplified. The males are distinguished as having two DNA amplicons present, while females have only a single amplicon. The kit adapted for carrying out the method includes a pair of primers to amplify the locus and optionally polymerase chain reaction reagents.