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The Application of Genetic Tests in an Assisted Reproduction Unit: DNA Methylation Defects
Published in Nicolás Garrido, Rocio Rivera, A Practical Guide to Sperm Analysis, 2017
Cristina Camprubí, Joan Blanco
Under certain conditions of pH and temperature, the sodium bisulfite converts the unmethylated cytosines (C) into uracil (U) by sulfonation, desulfonation, and deamination reactions (Figure 10.2). When the modified DNA is amplified by PCR, the C residues that are methylated are amplified as C and present a guanine (G) as a complementary base. On the contrary, the nonmethylated C turned to U are amplified as thymine (T) and presented an adenine (A) as complementary base. When analyzing the sequence of the PCR product, methylated/nonmethylated cytosine residues can be distinguished depending on the presence of C/G or A/T.
Analytical validation of a novel multi-target blood-based test to detect hepatocellular carcinoma
Published in Expert Review of Molecular Diagnostics, 2021
Andrea M. Johnson, Jeanne M. Dudek, David K. Edwards, Theran A. Myers, Patrick Joseph, Jennifer J. Laffin, Janelle J. Bruinsma
For the methylation marker workflow, DNA was extracted from 5–6 mL plasma or plasma surrogate using the QIAsymphony® SP instrument platform and reagents (Qiagen, Hilden, Germany). The DNA was transferred to the Hamilton® Microlab STARlet (Hamilton Robotics, Reno, NV) for bisulfite treatment, desulfonation, and subsequent re-purification using reagents manufactured by Exact Sciences Corporation (Madison, WI) [18]. To interrogate the methylation markers, 20 µL of the re-purified, bisulfite-converted DNA was amplified in one triplex assay – two HCC methylated DNA markers (MDMs), or regions of DNA that are hypermethylated in cancer cells compared to healthy cells, plus the constitutively methylated B3GALT6 reference marker – using the Long-probe Quantitative Amplified Signal (LQAS) chemistry. LQAS, which was run using the Quantstudio™ 5 Real-Time PCR Instrument (Life Technologies Corporation, Grand Island, NY) and reagents manufactured by Exact Sciences Corporation [18], combines amplification using real-time PCR and allele-specific detection of methylated target DNA through an invasive cleavage assay.
Single pot synthesized gold nanoparticles using Hippophae rhamnoides leaf and berry extract showed shape-dependent differential nanobiotechnological applications
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Further, 4-ABS may undergo desulfonation to form aniline (m/z 93) and sulfonic acid which are further mineralized to sulfurous acid (m/z 42) (Figure 9(D)). p-PDA undergoes deamination to form m-hydroxy benzoic acid ethyl ester (HBA, m/z 121) or aniline (m/z 93), which are transformed into short-chain carboxylic acids by oxidative ring opening, ultimately degrading to inorganic ions (sulfate, nitrate and ammonium), CO2 and H2O (Figure 9(D)). Figure 9(C) depicts structures of major identified products formed after the dye degradation.
Disposition study of the novel dipeptidyl peptidase 4 inhibitor cetagliptin in rats
Published in Xenobiotica, 2022
Jinmiao Lu, Yan Hao, Fuzhi Zhang, Huiping Pan, Juping Ding, Qiang Yu, Tong Wang
HPLC retention time ∼39.2 min was the metabolite M500 in BDC SD rats. LC/(+)ESI-FTMS analysis of the protonation [12C-M + H]+ was 501.1025 Da, which was consistent with C18H19O4N4F6S (error was −0.1256 ppm) and suggested that M500 was N- sulphate of the parent drug. M500 produced the loss of fluorine to give m/z 483/485 and 465/467. Desulfonation of M500 produced m/z 421/423. All fragment ions were consistent with M500.