Cardiac channel gene screen using PCR, dHPLC, and direct DNA
COLD-PCR, DHPLC and GeneScanning
JerryApril 28, 20210 Comments
The use of COLD-PCR, DHPLC and GeneScanning for the highly sensitive detection of c-KIT somatic mutations in canine mast cell tumours.
The conventional polymerase chain reaction (PCR)/sequencing methods may be poorly suited for the detection of somatic mutations in canine mast cell tumour (MCT) samples owing to limited sensitivity. This study was aimed at establishing novel and more sensitive methods, assessing their limit of detection and comparing their sensitivity with conventional methods.Two different ‘driver’ somatic mutations of c-KIT, together with the wild-type counterparts, were cloned in plasmids to prepare standard samples with known concentrations of mutated alleles in a background of wild-type alleles; the plasmids standards were assayed using either conventional or novel, highly sensitive technique.
Conventional PCR/sequencing showed a sensitivity of 50-20%. Conversely, all the novel methods obtained higher sensitivities allowed reaching as low as 2.5-1.2% of the mutated DNA.The study demonstrates that early conventional methods could likely have underestimated the prevalence of KIT mutations of MCTs, therefore affecting the assessment of their relevance in prognosis and tyrosine kinase inhibitor (TKI) treatment effectiveness.
Efficient IDUA Gene Mutation Detection with Combined Use of dHPLC and Dried Blood Samples.
Objectives. Development of a simple mutation directed method in order to allow lowering the cost of mutation testing using an easily obtainable biological material. Assessment of the feasibility of such method was tested using a GC-rich amplicon. Design and Methods. A method of denaturing high-performance liquid chromatography (dHPLC) was improved and implemented as a technique for the detection of variants in exon 9 of the IDUA gene. The optimized method was tested in 500 genomic DNA samples obtained from dried blood spots (DBS).
Results. With this dHPLC approach it was possible to detect different variants, including the common p.Trp402Ter mutation in the IDUA gene. The high GC content did not interfere with the resolution and reliability of this technique, and discrimination of G-C transversions was also achieved. Conclusion. This PCR-based dHPLC method is proved to be a rapid, a sensitive, and an excellent option for screening numerous samples obtained from DBS. Furthermore, it resulted in the consistent detection of clearly distinguishable profiles of the common p.Trp402Ter IDUA mutation with an advantageous balance of cost and technical requirements.
Description: This is Double-antibody Sandwich Chemiluminescent immunoassay for detection of Human Filaggrin (FLG) in Tissue homogenates and other biological fluids.
Description: This is Double-antibody Sandwich Chemiluminescent immunoassay for detection of Human Filaggrin (FLG) in Tissue homogenates and other biological fluids.
Description: This is Double-antibody Sandwich Chemiluminescent immunoassay for detection of Human Filaggrin (FLG) in Tissue homogenates and other biological fluids.
Description: This is Double-antibody Sandwich Chemiluminescent immunoassay for detection of Human Filaggrin (FLG) in Tissue homogenates and other biological fluids.
Description: Double-antibody Sandwich chemiluminescent immunoassay for detection of Human Filaggrin (FLG)Tissue homogenates and other biological fluids
Description: A sandwich quantitative ELISA assay kit for detection of Human Filaggrin (FLG) in samples from tissue homogenates, cell lysates, cell culture supernates or other biological fluids.
Description: A sandwich quantitative ELISA assay kit for detection of Human Filaggrin (FLG) in samples from tissue homogenates, cell lysates, cell culture supernates or other biological fluids.
Description: Quantitativesandwich ELISA kit for measuring Human Filaggrin (FLG) in samples from serum, plasma, tissue homogenates, cell lysates. A new trial version of the kit, which allows you to test the kit in your application at a reasonable price.
Description: Quantitativesandwich ELISA kit for measuring Human Filaggrin(FLG) in samples from serum, plasma, tissue homogenates, cell lysates. Now available in a cost efficient pack of 5 plates of 96 wells each, conveniently packed along with the other reagents in 5 separate kits.
Use of PCR-DHPLC with fluorescence detection for the characterization of the bacterial diversity during cassava (Manihot esculenta Crantz) fermentation.
Denaturing high-performance liquid chromatography (DHPLC) has been described as a suitable method to study DNA polymorphisms. Here, cassava (Manihot esculenta Crantz) fermentation liquor was examined using DHPLC analysis to characterize the bacterial diversity during the fermentation process. GC-clamped amplicons corresponding to a variable region of the bacterial community 16S rDNA were synthesized using polymerase chain reaction (PCR) and then resolved on a base-composition basis using preparative DHPLC.
Eluate fractions were collected at random and used as a source of whole community DNA that could be used to determine the bacterial diversity. As a first approach, GC-clamps were removed from the eluted DNA fragments using PCR to avoid the possible bias these clamps could cause during the construction of clone libraries. As a second approach, a clone library of each eluate sample was constructed, preserving the GC-clamps of the DNA fragments.
The first approach generated 132 bacterial rDNA sequences with an average size of 200 bp, 45% of which had similarity to unculturable or non-classified bacteria. The second approach produced 194 sequences identified as Proteobacteria (48%), uncultured or non-classified environmental bacteria (40%) and Firmicutes (12%).
We detected a remarkably greater bacterial diversity using the first approach than the second approach. The DHPLC-PCR method allowed for the fast and non-laborious detection of a vast bacterial diversity that was associated with cassava fermentation, and we conclude that it is a promising alternative for the characterization of the overall microbial diversity in complex samples.
Use of denaturing high-performance liquid chromatography (DHPLC) to characterize the bacterial and fungal airway microbiota of cystic fibrosis patients.
The aim of this study was to evaluate the use of denaturing high-performance liquid chromatography (DHPLC) to characterize cystic fibrosis (CF) airway microbiota including both bacteria and fungi. DHPLC conditions were first optimized using a mixture of V6, V7 and V8 region 16S rRNA gene PCR amplicons from 18 bacterial species commonly found in CF patients.
Then, the microbial diversity of 4 sputum samples from 4 CF patients was analyzed using cultural methods, cloning/sequencing (for bacteria only) and DHPLC peak fraction collection/sequencing. DHPLC analysis allowed identifying more bacterial and fungal species than the classical culture methods, including well-recognized pathogens such as Pseudomonas aeruginosa.
Even if a lower number of bacterial Operational Taxonomic Units (OTUs) was identified by DHPLC, it allowed to find OTUs unidentified by cloning/sequencing. The combination of both techniques permitted to correlate the majority of DHPLC peaks to defined OTUs.
Finally, although Aspergillus fumigatus detection using DHPLC can still be improved, this technique clearly allowed to identify a higher number of fungal species versus classical culture-based methods. To conclude, DHPLC provided meaningful additional data concerning pathogenic bacteria and fungi as well as fastidious microorganisms present within the CF respiratory tract. DHPLC can be considered as a complementary technique to culture-dependent analyses in routine microbiological laboratories.
DHPLC and MS studies of a photoinduced intrastrand cross-link in DNA labeled with 5-bromo-2′-deoxyuridine.
It is well known that the replacement of thymidine with 5-bromo-2′-deoxyuridine (BrdU) in DNA sensitizes it to UVB light. Irradiation of a biopolymer substituted in such a way leads to manifold kinds of DNA damage, such as intrastrand cross-links, single- and double-strand breaks or alkali-labile sites that were studied in the past with a broad spectrum of analytical methods.
Here, we demonstrate that completely denaturing high-performance liquid chromatography (DHPLC), underestimated so far in DNA damage studies, could act as an inexpensive, and high-resolution substitute for the commonly employed gel electrophoresis.
We report on the DHPLC/mass spectrometry (MS) analyses of photolytes obtained with the UV irradiation of aqueous solutions containing 40 base pairs of a long, double-stranded oligonucleotide labeled with BrdU in one of its strands.
The UV-product was detected by HPLC at a temperature of 70°C. Subsequent MS analysis with electrospray ionization (ESI-MS) of the photolyte, enzymatic digestion of the irradiated material and HPLC and MS analysis (LC-MS) of the digest demonstrated unequivocally that an intrastrand covalent dimer, involving adenine and uracil, is formed in the irradiated system.
