PATERNITY TESTING BY THE DETECTION OF D1S80 VNTR USING FLUORESCENCE IMAGE ANALYZER (DUALCOLOUR SYSTEM)

An improved method for DNA polymorphism typing of D1S80 VNTR locus and its application to paternity testing are described. For accurate esti mation of the length of polymorphic DNA fragments, the size marker was labeled with fluorescence different from that of PCR primers, and co- electrophoresed as an internal standard. The dualcolour system of fluo rescence image analyzer was used to detect the fragments and determine their size. This internal marker method could successfully overcome t he problems of band pattern distortion and tailing, besides it allows easy and accurate interpretation of the DNA types. Our results indicat e that the internal marker method is much more accurate than the metho d of using size marker in gel, even with the presence of distortion or tailing of the band patterns. Family studies applying this method sho wed complete agreement between the observed and predicated types.