Platforms and Protocols for the Multidimensional Microchip Electrophoretic Analysis of Complex Proteomes

The need for rapid, portable and high-throughput systems in proteomics is now prevalent because of demands for generating new protein-based disease biomarkers. However, 2-D protein profile patterns are lending themselves as potential diagnostic tools for biomarker discovery. It is difficult to identify protein biomarkers which are low abundant in the presence of highly abundant proteins, especially in complex biological samples like serum. Protein profiles from 2-D separation of the protein content of cells or body fluids, which are unique to certain physiological or pathological states, are currently available on internet databases. In this work, we demonstrate the ability to separate a complex biological sample using low cost, disposable, polymer-based microchips suitable for a multidimensional techniques that employed sodium dodecyl sulfate micro-capillary gel electrophoresis (SDS µ-CGE) in the 1st dimension and micellar electrokinetic capillary chromatography (MEKC) or microemulsion electrokinetic capillary chromatography (MEEKC) in the 2nd dimension. The peak capacity generated by this microchip technique was about 3-fold greater compared to conventional 2-D separation methods and the complete separation time was 60X faster. To minimize electroosmotic flow effects, we dynamically coated the channels with methylhydroxyethyl cellulose. Proteins were detected by laser-induced fluorescence following their labeling with dyes. To mitigate challenges posed by labeling the proteins, we investigated the use of a label-free technique that relied upon conductivity measurements. Preliminary data are presented on the fabrication of on-chip electrodes using a conductive SU-8 polymer via lithography

Linking Workplace Diversity To Organizational Performance: A Conceptual Framework

This article investigates the previous research of the influence of workplace diversity on organizational performance. It provides a conceptual framework of the influence of diversity on performance, integrating the literature on the potential performance benefits of diversity and potential problems of diversity. The goal of the article is to provide practitioners and scholars alike with a framework that will allow them to design diversity initiatives based on a needs assessment and empirical researc

Gender-based impacts of COVID-19 in Sub- Saharan Africa

The lasting educational and economic impacts of COVID-19 have disproportionally disadvantaged girls on the fringes of society, extending beyond the period of imposed lockdowns. This study delves deeper into the education, socio-economic, and gender-specific effects of the COVID-19 pandemic within the context of Sub-Saharan Africa (SSA). The research illuminates how the pandemic has influenced economic activities and the roles of teachers, parents, and students in the educational process. Furthermore, the paper examines the efficacy of distance learning across diverse media in SSA. The findings suggest that children from rural settings might have limited resources to adapt and continue their education during school closures. Marginalized girls are substantially more likely than their male counterparts to leave school altogether due to these closures, placing girls and women at a heightened risk of experiencing the most severe outcomes of the pandemic. Female education has been notably disrupted due to the rise in child labor, violence, and pregnancies amidst the pandemic

EndoV/DNA ligase mutation scanning assay using microchip capillary electrophoresis and dual-color laser-induced fluorescence detection

We report the ability to detect with high sensitivity sporadic mutations using a mutation scanning assay, which employs thermostable endonuclease V (EndoV) and DNA ligase. The products of the mutation scanning assay were separated using microchip capillary electrophoresis (mu CE) and detected with a dual-color laser-induced fluorescence (LIF) detector. PCR products from mutant and wild-type DNA of p53 exon 8 were generated using Cy3-labeled forward and Cy5-labeled reverse primers to allow LIF detection with mCE. EndoV recognizes and primarily cleaves heteroduplexed DNA one base 30 to a mismatch and can nick matched sites at low levels as well. DNA ligase is used to reseal nicks generated at matched sites, which creates a highly sensitive and specific assay for analyzing sporadic mutations in genomic DNA. Heteroduplexed DNA samples were treated with EndoV alone and with both EndoV and DNA ligase and separated using a 4% (w/v) linear polyacrylamide gel constituted in 1x TTE buffer, 7 M urea, and 0.05% (w/v) methyl hydroxyethyl cellulose, which was used to suppress the EOF in the microchip. Sizing of the bands appearing in the electropherogram revealed the approximate position of the mutation. In this study, mutations present in p53 exon 8 generated Cy3-labeled cleavage products of 158 nt and Cy5-labeled cleavage products of 195 nt. The DNA fragments were simultaneously monitored at their respective color using a dual-color LIF system with the 158 and 195 nt fragments detected along with heteroduplexed fragments of 350 nt. The microchip separation was completed within 7 min, almost tenfold shorter time compared to conventional capillary gel electrophoresis.close7

Ultra-fast two-dimensional microchip electrophoresis using SDS mu-CGE and microemulsion electrokinetic chromatography for protein separations

A poly(methyl methacrylate) microfluidic chip was used to perform a two-dimensional (2-D) separation of a complex protein mixture in short development times. The separation was performed by combining sodium dodecyl sulfate micro-capillary gel electrophoresis (SDS mu-CGE) with microemulsion electrokinetic chromatography (mu-MEEKC), which were used for the first and second dimensions, respectively. Fluorescently labeled Escherichia coli cytosolic proteins were profiled by this 2-D approach with the results compared to a similar 2-D separation using SDS mu-CGE x mu-MEKC (micelle electrokinetic chromatography). The relatively short column lengths (effective length = 10 mm) for both dimensions were used to achieve separations requiring only 220 s of development time. High spot production rates (131 +/- 11 spots min(-1)) and reasonable peak capacities (481 +/- 18) were generated despite the fact that short columns were used. In addition, the use of mu-MEEKC in the second dimension was found to produce higher peak capacities compared to mu-MEKC (481 +/- 18 for mu-MEEKC and 332 +/- 17 for mu-MEKC) due to the higher plate numbers associated with mu-MEEKC.close7

IL-10, IL-6 and CD14 polymorphisms and sepsis outcome in ventilated very low birth weight infants

<p>Abstract</p> <p>Background</p> <p>Genetic variation in the innate immune system of the host may play a role in determining the risk of developing infection, as well as outcome from infection.</p> <p>Methods</p> <p>Infectious complications were retrospectively determined in 293 (233 African-American (AA), 57 Caucasian and 3 Hispanic) mechanically ventilated very low birth weight (VLBW) infants (<1500 grams at birth) who were genotyped for the IL-6 -174 G/C, IL-10 -1082 G/A and CD14 -260 C/T single nucleotide polymorphisms (SNPs).</p> <p>Results</p> <p>The IL-6 -174C allele was associated with an increased incidence of late blood stream infection (BSI) in AA but not Caucasian infants. In AA infants with the C allele the incidence of late BSI was 20/29 (69%) compared to 94/204 (46%) in homozygous GG infants (RR 2.6, 95% CI: 1.1–6.0, p = 0.021). The IL-10 -1082A allele was associated with an increased incidence of late BSI. One or more episodes of late BSI developed in 14 (35%) of 40 infants with the GG genotype, 71 (49%) of 145 infants with the GA genotype and 63 (58%) of 108 infants with the AA genotype (p = 0.036). Infants with the A allele (AA or GA genotypes) had an incidence of late BSI that was 134/253 (53%) compared to 14/40 (35%) in homozygous GG infants (RR 2.1, 95% CI: 1.04–4.19, p = 0.035). The CD14 -260 C/T SNP did not alter the overall risk for BSI in ventilated VLBW infants. Multiple BSI episodes were more common in the TT genotype group (CC: 17%, CT: 11%, TT: 30%, p = 0.022). This effect was due to the strong effect of the TT genotype on the incidence of multiple BSI in AA infants (CC: 15%, CT: 11%, TT: 39%, p = 0.003).</p> <p>Conclusion</p> <p>The IL-6 -174 G/C, IL-10 -1082 G/A and CD14 -260 C/T SNPs may alter risk for BSI in ventilated VLBW infants.</p