The single-strand conformation polymorphism (SSCP), accompanied by sequencing, is a useful methods for identifying mutations in a DNA fragment. In this study, we have developed a modified SSCP with the aid of sodium bisulfite treatment. The corresponding PCR products for exon 3 of Hb gene were sequenced and samples with homozygote and heterozygote single nucleotide substitutions were identified. The PCR products were treated with sodium bisulfite, which deaminates all the cytosine residues. The reaction mixture was then analyzed on non-denaturing polyacrylamide gels. The modified method, which is called deaminated SSCP (DSSCP), was applied successfully in analysis of mutations in the beta-globin gene at positions relevant to codon 6. DSSCP is a very effective and reproducible method providing clear results that are easy to interpret without the involvement of radioactivity.