Search PubMed⌕ Search

Biomedical subjects

B Gharizadeh

Publications and source records attributed to B Gharizadeh.

2 recordsLinked to original sources

Mutation detection by pyrosequencing: sequencing of exons 5-8 of the p53 tumor suppressor gene.

The ability to sequence a large number of DNA samples rapidly and accurately for detection of all possible mutations is a critical goal for the future application of DNA sequencing in routine medical diagnostics. Pyrosequencing() is a non-electrophoretic real-time DNA sequencing method that uses the luciferase-luciferin light release as the detection signal for nucleotide incorporation into target DNA. For pyrosequencing of the human p53 gene, a nested multiplex PCR method for amplification of exons 5-8 was prepared. In order to investigate the use of pyrosequencing in mutation detection, DNA samples from skin-cancer patients were used. Two forms of nucleotide dispensation strategy were used, cyclic and programmed. Bi-directional pyrosequencing was performed and the overlapping sequence data produced were assembled to determine the sequence of the gene. Reliable sequencing data were obtained with both dispensation strategies, but some advantages were obtained using the programmed nucleotide dispensation approach, such as longer and faster reads, and fewer out-of-phase problems. The accuracy of pyrosequencing for detection of p53 mutations and allele distribution was demonstrated.

Base Sequence↗

Single-nucleotide polymorphism analysis by pyrosequencing.

There is a growing demand for high-throughput methods for analysis of single-nucleotide polymorphic (SNP) positions. Here, we have evaluated a novel sequencing approach, pyrosequencing, for such purposes. Pyrosequencing is a sequencing-by-synthesis method in which a cascade of enzymatic reactions yields detectable light, which is proportional to incorporated nucleotides. One feature of typing SNPs with pyrosequencing is that each allelic variant will give a unique sequence compared to the two other variants. These variants can easily be distinguished by a pattern recognition software. The software displays the allelic alternatives and allows for direct comparison with the pyrosequencing raw data. For optimal determination of SNPs, various protocols of nucleotide dispensing order were investigated. Here, we demonstrate that typing of SNPs can efficiently be performed by pyrosequencing using an automated system for parallel analysis of 96 samples in approximately 5 min, suitable for large-scale screening and typing of SNPs.

Base Sequence↗