A robust strategy for screening and confirmation of familial defective apolipoprotein B-100

1993 ◽  
Vol 39 (1) ◽  
pp. 118-121 ◽  
Author(s):  
C D Mamotte ◽  
F M van Bockxmeer

Abstract The diagnosis of familial defective apolipoprotein B-100 (FDB) has been facilitated by the use of mutagenic polymerase chain reaction (PCR) primers to introduce restriction sites at the FDB gene locus. We describe a two-test strategy for diagnosing FDB that overcomes the potential for error in single-test methods based on such techniques. We introduce an Sau96I restriction site for PCR products of the normal apolipoprotein B allele. Incomplete digestion of the PCR product with Sau96I suggests an FDB heterozygote, although a false-positive result due to nonideal digestion conditions remains a possibility. In such cases we use a second test that introduces an ScaI restriction site in PCR products of the FDB allele. The diagnosis is confirmed if half of this product can be digested with ScaI. Both tests use 0.25 units of Taq polymerase and are robust with respect to annealing temperature (31-58 degrees C) and to Mg2+ concentration (1.0-3.2 mmol/L).

2017 ◽  
Author(s):  
Charles Hodgens ◽  
Zachary L. Nimchuk ◽  
Joseph J. Kieber

AbstractGenetic manipulation of organisms using CRISPR/Cas9 technology generally produces small insertions/deletions (indels) that can be difficult to detect. Here, we describe a technique to easily and rapidly identify such indels. Sequence-identified mutations that alter a restriction enzyme recognition site can be easily distinguished from wild-type alleles using a cleaved amplified polymorphic sequence (CAPS) technique. If a restriction site is created or altered by the mutation such that only one allele contains the restriction site, a polymerase chain reaction (PCR) followed by a restriction digest can be used to distinguish the two alleles. However, in the case of most CRISPR-induced alleles, no such restriction sites are present in the target sequences. In this case, a derived CAPS (dCAPS) approach can be used in which mismatches are purposefully introduced in the oligonucleotide primers to create a restriction site in one, but not both, of the amplified templates. Web-based tools exist to aid dCAPS primer design, but when supplied sequences that include indels, the current tools often fail to suggest appropriate primers. Here, we report the development of a Python-based, species-agnostic web tool, called indCAPS, suitable for the design of PCR primers used in dCAPS assays that is compatible with indels. This tool should have wide utility for screening editing events following CRISPR/Cas9 mutagenesis as well as for identifying specific editing events in a pool of CRISPR-mediated mutagenesis events. This tool was field-tested in a CRISPR mutagenesis experiment targeting a cytokinin receptor (AHK3) in Arabidopsis thaliana. The tool suggested primers that successfully distinguished between wild-type and edited alleles of a target locus and facilitated the isolation of two novel ahk3 null alleles. Users can access indCAPS and design PCR primers to employ dCAPS to identify CRISPR/Cas9 alleles at http://indcaps.kieber.cloudapps.unc.edu/.


1993 ◽  
Vol 11 (2-3) ◽  
pp. 139-141 ◽  
Author(s):  
L. Saksova ◽  
J. Gecz ◽  
L. Kadasl ◽  
V. Ferak

Recently, a pair of PCR primers have been described that make it possible to amplify a highly polymorphic VNTR locus DX552 (St14). PCR products range in size from approximately 650 to 3000 bp. Ninety X chromosomes from unrelated Caucasian subjects were investigated. Digestion of the PCR products with TaQI revealed the presence of a polymorphic TaQI restriction site within the product 200 bp from the end. This restriction site is present on 60% and absent on 40% of all alleles, but the absence is confined solely to the alleles 1690 bp (39%) and 2100 bp (1%). Thus, there is a strong allelic association between the most frequent 1690 bp allele and the absence of the TaQI restriction site. Determination of this polymorphisms within the St 14 VNTR region increases the expected heterozygosity at the DXS52 locus from 72% to 80%. This increases the fraction of hemophilia A families where this marker is informative for indirect prenatal diagnosis and carrier identification.


2021 ◽  
Vol 13 (2) ◽  
pp. 192-200
Author(s):  
Anggi Laksmita Dewi ◽  
Dewi Kartikawati Paramita ◽  
Jajah Fachiroh

BACKGROUND: Single nucleotide variations (SNV) have been mapped to be associated with several human conditions and diseases. To validate the association between SNV to certain human traits or diseases, a large number of subjects must be included. Thus, in need of a fast, relatively economic, and reliable genotyping method. This can be achieved through the use of tetra-primer amplification refractory mutation system polymerase chain reaction (Tetra-primer ARMS PCR). This study reports strategy to develop Tetra-primer ARMS PCR-based genotyping of CHRNA3 rs8040868.METHODS: The optimization of Tetra-primer ARMS PCR was done through these steps: identification of gene sequence and position of single mutation; designing outer and inner PCR primers; amplification of target gene fragments through PCR by using outer primer; confirming genotype of the PCR product by using sequencing; determining an optimum ratio of outer and inner primer; and determining optimum annealing temperature and cycles for the PCR program. The PCR products were run in 2% gel agarose electrophoresis and visualized under UV illumination.RESULTS: Outer and inner primer ratio of 1:3 with annealing temperature of 64.4°C and 40x cycles was found to be the most optimum condition. Tetra-primer ARMS PCR was able to confirm the results of the DNA sequence of 2 samples, confirming wild-type variants (TT allele) and the heterozygous mutant (CT allele).CONCLUSION: Tetra-primer ARMS PCR was able to genotype rs8040868 of the CHRNA3 gene.KEYWORDS: tetra-primer ARMS PCR, CHRNA3, rs8040868, genotyping


1992 ◽  
Vol 38 (5) ◽  
pp. 687-694 ◽  
Author(s):  
C P Vary

Abstract This method for rapid, automated analysis of polymerase chain reaction (PCR) products makes use of PCR primers containing 5'-polypyrimidine sequences. Polypyrimidine-"headed" primers confer to the PCR product the ability to form triple helical complexes with a third polypyrimidine oligonucleotide. Third-strand oligonucleotides are modified to serve as either capture reagents or detection reagents for PCR products. Automated quantitative measurement of the PCR product is achieved by using latex bead-based fluorescence analysis. The use of triple-instead of double-helical interactions avoids the usual requirements of complex blocking reagents, time- and labor-intensive washing steps, and long times for color development. The method also provides rapid, sequence-specific capture and detection of PCR products without the need to denature the double-stranded PCR product. The assay is demonstrated with use of both PCR primer-derived and endogenous triple-helix-forming sequences resulting from PCR of several bacterial and viral target nucleic acids.


1989 ◽  
Vol 86 (17) ◽  
pp. 6691-6695 ◽  
Author(s):  
B Davies ◽  
S Feo ◽  
E Heard ◽  
M Fried

We have devised a strategy that utilizes the polymerase chain reaction (PCR) for the detection and isolation of intron-containing genes in the presence of an abundance of processed pseudogenes. The method depends on the genomic DNA sequence between the PCR primers spanning at least one intron in the gene of interest, resulting in the generation of a larger intron-containing PCR product in addition to the smaller PCR product amplified from the intronless pseudogenes. A unique intron probe isolated from the larger PCR product is used for the detection of intron-containing clones from recombinant DNA libraries that also contain pseudogene clones. This method has been used successfully for the selective isolation of an intron-containing rat L19 ribosomal protein gene in the presence of multiple pseudogenes. Analysis of a number of mammalian ribosomal protein multigene families by PCR indicates that they all contain only a single gene with introns.


1996 ◽  
Vol 8 (4) ◽  
pp. 460-463 ◽  
Author(s):  
Mark A. Franklin ◽  
David H. Francis ◽  
Diane Baker ◽  
Alan G. Mathew

The objective of this study was to develop a polymerase chain reaction (PCR)-based method to detect and differentiate among Escherichia coli strains containing genes for the expression of 3 antigenic variants of the fimbrial adhesin K88 (K88ab, K88ac, and K88ad). Five primers were designed that allowed detection of K88+ E. coli, regardless of antigenic variant, and the separate detection of the ab, ac, and ad variants. Primers AM005 and AM006 are 21 base pair (bp) oligomers that correspond to a region of the K88 operon that is common to all 3 antigenic variants. Primers MF007, MF008, and MF009 are 24-bp oligomers that matched variable regions specific to ab, ac, and ad, respectively. Using primers AM005 and AM006, a PCR product was obtained that corresponds to a 764-bp region within the large structural subunit of the K88 operon common to all 3 antigenic variants. Primer AM005 used with MF007, MF008, or MF009 produced PCR products approximately 500-bp in length from within the large structural subunit of the K88 operon of the 3 respective antigenic variants. Fragments were identified by rates of migration on a 1% agarose gel relative to each other as well as to BstEII-digested lambda fragments. This PCR-based method was comparable to the enzyme-linked immunosorbent assay and western blot test in the ability to differentiate between the antigenic variants. K88+ E. coli were differentiated from among laboratory strains and detected in ileal samples taken from cannulated pigs challenged with a known K88+ variant. K88+ E. coli were also detected from fecal swabs taken from newly weaned pigs, thus confirming that this PCR-based test could provide a convenient clinical assay for the detection of K88+ E. coli. Detection and differentiation of K88+ E. coli using general and specific primers was successful. PCR methods of detection should permit identification of K88+ antigenic variants regardless of the level of expression of the antigen.


1993 ◽  
Vol 39 (9) ◽  
pp. 1927-1933 ◽  
Author(s):  
J B Findlay ◽  
S M Atwood ◽  
L Bergmeyer ◽  
J Chemelli ◽  
K Christy ◽  
...  

Abstract An automated system for polymerase chain reaction (PCR) amplification and detection combats false-positive results caused by "PCR product carryover." The system uses a single vessel for both PCR amplification and the subsequent detection of PCR products, eliminating the need to handle PCR products in an open environment and risk product carryover. The sample and PCR reagents are introduced into one compartment within the vessel, and amplification occurs as they are thermally cycled. Other compartments contain the reagents for detection of PCR products. Pressure from a roller provides for sequential delivery of the contents of the compartments to a detection area. The PCR products are biotinylated at their 5' ends during amplification through the use of biotinylated primers. After delivery to the detection area, they are specifically captured by hybridization with immobilized oligonucleotide probes. Subsequent reaction with streptavidin-horseradish peroxidase conjugate forms a complex that catalyzes dye formation from dye precursor. Wash steps minimize nonspecific background. This format is amenable to multiplexing, permitting internal controls, speciation of bacteria, typing of viruses, and panel testing. An HIV assay performed with this system demonstrated 100% sensitivity and 95% specificity for 64 patients' samples relative to a conventional PCR assay based on 32P solution hybridization. Similarly, an automated closed-vessel assay of cytomegalovirus exhibited 97.5% sensitivity and 100% specificity.


1997 ◽  
Vol 9 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Daria H. Black ◽  
R. Eberle

A rapid method for detection and differentiation of 5 primate αpha-herpesviruses (human herpes simplex virus types 1 and 2 [HSV1, HSV2], green monkey simian agent 8, baboon herpesvirus 2 [HVP2], and macaque B virus [BV]) was developed utilizing the polymerase chain reaction (PCR). PCR primers were located in conserved regions of the gene encoding the glycoprotein B, which flanks an intervening region that is highly divergent among the 5 viruses. Amplified PCR products from the 5 viruses were readily differentiated by their unique restriction enzyme digestion patterns. No variation in digestion patterns was noted among strains of HSV1, HSV2, or HVP2. One clinical isolate of BV exhibited variation in a single restriction site, but its overall restriction pattern remained typical of BV. This method (PCR/RFLP) allowed the presence of herpesvirus DNA in clinical swabs from primates to be readily detected and the virus unambiguously identified.


2002 ◽  
Vol 65 (7) ◽  
pp. 1158-1165 ◽  
Author(s):  
S. LAHIFF ◽  
M. GLENNON ◽  
J. LYNG ◽  
T. SMITH ◽  
N. SHILTON ◽  
...  

We describe a real-time polymerase chain reaction (PCR) assay for the detection of bovine DNA extracted from meat and bone meal (MBM) samples. PCR primers were used to amplify a 271-bp region of the mitochondrial ATPase 8–ATPase 6 gene, and a fluorogenic probe (BOV1) labeled with a 5′ FAM reporter and a 3′ TAMRA quencher was designed to specifically detect bovine PCR product. The specificity of the BOV1 probe for the detection of the bovine PCR product was confirmed by Southern blot hybridization analysis of the probe with PCR products generated from ovine, porcine, and bovine genomic DNA extracted from blood and with PCR products generated from genomic DNA extracted from single-species laboratory scale rendered MBM samples. The specificity of the BOV1 probe was also evaluated in real-time PCR reactions including these genomic targets. Both methods demonstrated that the BOV1 probe was specific for the detection of bovine PCR product. The BOV1 probe had a detection limit of 0.0001% bovine material by Southern blot DNA probe hybridization analysis and a detection limit of 0.001% bovine material in the real-time PCR assay. Application of the real-time PCR assay to six industrial samples that had previously tested positive for the presence of bovine material with a conventional PCR assay yielded positive results with the real-time PCR assay for four samples.


1999 ◽  
Vol 124 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Thomas Horejsi ◽  
Jodie M. Box ◽  
Jack E. Staub

The conversion of randomly amplified polymorphic DNA (RAPD) markers to sequence characterized amplified region (SCAR) markers, and the effects of differing polymerase chain reaction (PCR) conditions were studied in cucumber (Cucumis sativus L.). Attempts were made to clone and sequence 75 RAPD PCR products to produce SCAR primers (16 to 22 nucleotides) designed to amplify original RAPD PCR products. The influence of template DNA source, purity, and concentration, MgCl2 concentration, Taq polymerase source, and type of thermocycler upon RAPD and SCAR marker performance was evaluated. Conversion of RAPD to SCAR markers was not universally successful, and SCAR primers reacted differently to varying PCR conditions. Only 48 (64%) of 75 RAPD markers were successfully converted to SCAR markers and 11 (15%) of these reproduced the polymorphism observed with the original RAPD PCR product. Moreover, some SCAR primer pairs produced multiple polymorphic PCR products. The band intensity of SCAR markers were brighter (P = 0.05) than their corresponding RAPD markers with only one exception. The SCAR markers examined were less influenced (P = 0.05) by MgCl2 concentration than their corresponding RAPD markers. However, some SCAR markers were more sensitive to reaction impurities than their RAPD counterparts and SCAR markers tended to be less readily visualized (decrease in frequency of visible PCR product) with low concentrations (1 and 2 mm) of template DNA than their corresponding RAPD markers. Neither the source of Taq nor the type of thermocycler used affected the performance of SCAR and RAPD markers. These data suggest that although SCAR markers may demonstrate enhanced performance over the RAPD markers from which they are derived, careful consideration must be given to both the costs and potential benefits of SCAR marker development in cucumber.


Sign in / Sign up

Export Citation Format

Share Document