Dataset Information

Real-time PCR genotyping using displacing probes.

ABSTRACT: Simple and reliable genotyping technology is a key to success for high-throughput genetic screening in the post-genome era. Here we have developed a new real-time PCR genotyping approach that uses displacement hybridization-based probes: displacing probes. The specificity of displacing probes could be simply assessed through denaturation analysis before genotyping was implemented, and the probes designed with maximal specificity also showed the greatest detection sensitivity. The ease in design, the simple single-dye labeling chemistry and the capability to adopt degenerated negative strands for point mutation genotyping make the displacing probes both cost effective and easy to use. The feasibility of this method was first tested by detecting the C282Y mutation in the human hemochromatosis gene. The robustness of this approach was then validated by simultaneous genotyping of five different types of mutation in the human beta-globin gene. Sixty-two human genomic DNA samples with nine known genotypes were accurately detected, 32 random clinical samples were successfully screened and 114 double-blind DNA samples were all correctly genotyped. The combined merits of reliability, flexibility and simplicity should make this method suitable for routine clinical testing and large-scale genetic screening.

SUBMITTER: Cheng J

PROVIDER: S-EPMC407835 | biostudies-other | 2004 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Real-time PCR genotyping using displacing probes.

Cheng Jinping J Zhang Yongyou Y Li Qingge Q

Nucleic acids research 20040415 7

Simple and reliable genotyping technology is a key to success for high-throughput genetic screening in the post-genome era. Here we have developed a new real-time PCR genotyping approach that uses displacement hybridization-based probes: displacing probes. The specificity of displacing probes could be simply assessed through denaturation analysis before genotyping was implemented, and the probes designed with maximal specificity also showed the greatest detection sensitivity. The ease in design, ...[more]

PMID: 15087493

Similar Datasets

Project description:BackgroundWhile improvements in genotyping technology have allowed for increased throughput and reduced time and expense, protocols remain hindered by the slow upstream steps of isolating, purifying, and normalizing DNA. Various methods exist for genotyping samples directly through blood, without having to purify the DNA first. These procedures were designed to be used on smaller throughput systems, however, and have not yet been tested for use on current high-throughput real-time (q)PCR based genotyping platforms. In this paper, a method of quantitative qPCR-based genotyping on blood without DNA purification was developed using a high-throughput qPCR platform.FindingsThe performances of either DNA purified from blood or the same blood samples without DNA purification were evaluated through qPCR-based genotyping. First, 60 different mutations prevalent in the Ashkenazi Jewish population were genotyped in 12 Ashkenazi Jewish individuals using the QuantStudio™12K Flex Real-Time PCR System. Genotyping directly from blood gave a call rate of 99.21%, and an accuracy of 100%, while the purified DNA gave a call rate of 92.49%, and an accuracy of 99.74%. Although no statistical difference was found for these parameters, an F test comparing the standard deviations of the wild type clusters for the two different methods indicated significantly less variation when genotyping directly from blood instead of after DNA purification. To further establish the ability to perform high-throughput qPCR based genotyping directly from blood, 96 individuals of Ashkenazi Jewish decent were genotyped for the same 60 mutations (5,760 genotypes in 5 hours) and resulted in a call rate of 98.38% and a diagnostic accuracy of 99.77%.ConclusionThis study shows that accurate qPCR-based high-throughput genotyping can be performed without DNA purification. The direct use of blood may further expedite the entire genotyping process, reduce costs, and avoid tracking errors which can occur during sample DNA purification.

Project description:Introduction:ABO blood group genotyping is a new technology in hematology that helps prevent adverse transfusion reactions in patients. Identification of antigens on the surface of red blood cells is based on serology; however, genotyping employs a different strategy and is aimed directly at genes that determine the surface proteins. ABO blood group genotyping by real-time PCR has several crucial advantages over other PCR-based techniques, such as high rapidity and reliability of analysis. The purpose of this study was to examine nucleotide substitutions differences by blood types using a PCR-based method on Kazakh blood donors. Methods:The study was approved by the Ethics Committee of the National Center for Biotechnology. Venous blood samples from 369 healthy Kazakh blood donors, whose blood types had been determined by serological methods, were collected after obtaining informed consent. The phenotypes of the samples included blood group A (n = 99), B (n = 93), O (n = 132), and AB (n = 45). Genomic DNA was extracted using a salting-out method. PCR products of ABO gene were sequenced on an ABI 3730xl DNA analyzer (Applied Biosystems). The resulting nucleotide sequences were compared and aligned against reference sequence NM_020469.2. Real-time PCR analysis was performed on CFX96 Touch™ Real-Time PCR Detection System (BioRad). Results:Direct sequencing of ABO gene in 369 samples revealed that the vast majority of nucleotide substitutions that change the ABO phenotype were limited to exons 6 and 7 of the ABO gene at positions 261, 467, 657, 796, 803, 930 and 1,060. However, genotyping of only three of them (261, 796 and 803) resulted in identification of major ABO genotypes in the Kazakh population. As a result, TaqMan probe based real-time PCR assay for the specific detection of genotypes 261, 796 and 803 was developed. The assay did not take into account several other mutations that may affect the determination of blood group, because they have a low occurrence rate and therefore have not been found in the population sample. Conclusion:Real-time PCR based method for fast and reliable ABO genotyping was developed. This assay may be used as a complement to classic serological blood typing.

Dataset Information

Real-time PCR genotyping using displacing probes.

Publications

Real-time PCR genotyping using displacing probes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets