If an entire exon is deleted without the presence of a mutation in the bordering exons, a splice-site mutation may be present in the bordering introns in the genomic DNA. This, too, must be analysed in NCF1-specific PCR amplicons. For protocols see [29, 30]. Some investigators apply screening for a mutation in a PCR product to select the fragment to be sequenced. For this purpose, single-strand conformation polymorphism analysis [31], denaturing high-pressure liquid chromatography [32] or high-resolution melting analysis [33] can be used. Single-strand conformation polymorphism

(SSCP) is based on the difference in electrophoresis profile between denatured patients’ PCR products and wild-type PCR Selleckchem GSK 3 inhibitor products in a polyacrylamide gel. PCR products with an aberrant migration pattern are then sequenced. Denaturing high-pressure liquid chromatography (DHPLC) is based on heteroduplex formation between a PCR product from a patient with a wild-type PCR product. In case the two PCR products differ, the elution profile of the heteroduplex over

a column will differ from the profile seen with a wild-type homoduplex. Such PCR products are then sequenced. High-resolution melting analysis is based on the difference in melting curves between hetero- and homoduplexes. However, as buy Maraviroc a lack of aberrant signal does not guarantee a wild-type sequence in the patient’s PCR product in any of these methods, such screening assays are not generally applied. Splice-site mutations found in genomic DNA should be confirmed for their effect on mRNA splicing by analysing the lack of one or more exons in the cDNA of the patient. Also, the presence of large deletions, usually based on the lack of PCR product formation, should be confirmed by an independent assay, such next as multiplex ligase-dependent probe amplification

[34] or array comparative genomic hybridization [35]. Restriction fragment length polymorphism (RFLP) analysis is also possible, but this technique is tedious, requires a great deal of freshly purified genomic DNA and does not always lead to unequivocal results. Multiplex ligase-dependent probe amplification (MLPA), with a set of probes annealing at different positions, analyses which parts of a gene or gene-surrounding sequences are still present. In array comparative genomic hybridization (ACGH), DNA from a test sample and from a normal reference sample are labelled differently with fluorescent dyes and are then hybridized to a set of probes on a glass slide. The ratio of the fluorescence intensity of the test DNA to that of the reference DNA is then calculated, to measure the copy number changes for a particular gene or gene fragment.