Application of iTRAQ multiple labeling and tandem mass spectrometry in proteomic research of human peripheral blood mononuclear cells / 生物医学工程学杂志

This paper is aimed to establish and optimize proteomic research platform using isobaric tags for relative and absolute quantitation (iTRAQ) so as to facilitate further proteomic research of human peripheral blood mononuclear cells (hPBMC). We collected hPBMC, after protein extraction and trypsin digestion, we labeled the samples with iTRAQ reagents and then subjected to mass spectrometry. In triplicates, thirty precursors were randomly selected and detected; as a result, 26, 28 and 29 peptides were respectively tagged with ITRAQ reporter ions. The labeling efficiencies ranged between 86.7%-96.7%, with no significant difference among the groups (P>0.05). The coefficient of variance for the relative ratios of peptides from different proteins was ranged from 7.6% to 25.5% and there were no significant differences across the groups (P>0.05). The coefficient of variance for the relative ratios of different peptides from the same protein was varied from 9.3% to 19.1% and the differences across groups were not significant (P>0.05). The labeling of iTRAQ combined with tandem mass spectrometry in PBMC was successful with favourable reproducibility and accuracy, which could lay a foundation for further proteomic study of hPBMC in autoimmune disorders.

Prenatal diagnosis and molecular cytogenetic analysis of a de novo isodicentric chromosome 18

Isodicentric chromosome 18 [idic[18]] is rare structural aberration. We report on a prenatal case described by conventional and molecular cytogenetic analyses. The sonography at 24 weeks of gestation revealed multiple fetal anomalies; radial aplasia and ventricular septal defect were significant features. Routine karyotyping showed a derivative chromosome replacing one normal chromosome 18. the parental karyotypes were normal, indicating that the derivative chromosome was de novo. Array comparative genomic hybridization [array-CGH] revealed 18p11.21[right wards arrow] qter]. Fluorescent in situ hybridization [FISH] confirmed that the derivative chromosome was idic[18]. Our report describes a rare isodicentric chromosome 18 and demonstrates that array-CGH is a useful complementary tool to cytogenetic analysis for reliable identifying derivative chromosome

Detection and analysis of genomic copy number variations in a 46,X0, +der(?) fetus by array-based comparative genomic hybridization / 基础医学与临床

Objective To understand genomic copy number variations (CNVs) and ascertain karyotype for a 46,X0, + der(?) fetus, and investigate possibility and superiority of array-based comparative genomic hybridization (array-CGH ) in clinical cytogenetic diagnosis. Methods G-banded chromosome analysis was carried out. The whole genome of the fetus was scanned and analysed by array-CGH. The results of array-CGH were confirmed by RT-qPCR. Results G-banded chromosome analysis showed that the fetal karyotype was 46,X0, +der(?). Array-CGH revealed the derivative chromosome as Y chromosome without CNVs. A total number of 118 submicroscopic CNVs were identified. Comparable results between array-CGH and RT-qPCR were obtained for 9 novel CNVs. Conclusion Comparing with conventional cytogenetic analysis, array-CGH is of high resolution, high-throughput and high accuracy, which provides a technical platform for accurate detection of submicroscopic chromosomal aberrations.