Following hematopoietic stem cell transplantation (HSCT), it is important to determine whether engraftment is successful and to track the dynamic changes of the graft. Tandem repeats such as minisatellites and microsatellites are currently the most established markers for chimerism application. We have developed a reliable method to quantitatively evaluate engraftment status in post-allogeneic HSCT patients using variable number of tandem repeat (VNTR) markers and "lab-on-a-chip" microfluidic electrophoresis technology. Following identification of an informative marker by conventional polymerase chain reaction (PCR), donor chimerism percentage was calculated based on a standard curve generated from artificially mixed patient-donor DNA-specific alleles in serial dilutions. All PCR products were mixed with commercial gel dye and loaded into Agilent DNA 1000 microfluidic LabChips for DNA sizing and quantitation. In 44 patients, separation of pretransplant and donor DNA fragments was resolved clearly and accomplished rapidly within 30min. Chimerism analysis using this platform is able to detect an amount as low as 6.3% donor DNA with acceptable coefficient of variation values. We also demonstrated concordant chimerism analysis findings using both microchip tandem repeats and real-time PCR quantitation of insertion-deletion polymorphisms. This microchip platform obviates the need for fluorescently labeled primers or any post-PCR sample manipulation. Quantitative monitoring of post-HSCT chimerism status using microfluidic electrophoresis is a useful tool for both large- and small-scale post-HSCT chimerism centers.
One of the most cited limitations of capillary (and microchip) electrophoresis is the poor sensitivity. This review continues to update this series of biennial reviews, first published in Electrophoresis in 2007, on developments in the field of on-line/in-line concentration methods in capillaries and microchips, covering the period July 2014-June 2016. It includes developments in the field of stacking, covering all methods from field amplified sample stacking and large volume sample stacking, through to isotachophoresis, dynamic pH junction, and sweeping. Attention is also given to on-line or in-line extraction methods that have been used for electrophoresis.
Human papillomavirus (HPV) is well known as an etiological factor for the development of anogenital carcinomas. The aim of our study was to compare the performance of USFDA approved Hybrid II (HCII) Assay and recently introduced DR. HPV Chip Kit for the detection of HPV DNA in clinical cervical scrapings from 40 patients. HPV DNA testing was performed using the automated HCII Assay system and DR. HPV Chip Kit. Taking cytological results as gold standard, it was found that HCII was more sensitive (36.4%) than DR. HPV Chip Kit (18.2%) although specificity was 100% with the latter method. In addition, both these molecular methods had comparable negative and positive predictive values. It was concluded that both HCII and DR. HPV Chip Kit have comparable specificity. However, sensitivity for detection of HPV in clinical samples with HCII is almost double as compared to DR. HPV Chip Kit.