We present "molecular threading", a surface independent tip-based method for stretching and depositing single and double-stranded DNA molecules. DNA is stretched into air at a liquid-air interface, and can be subsequently deposited onto a dry substrate isolated from solution. The design of an apparatus used for molecular threading is presented, and fluorescence and electron microscopies are used to characterize the angular distribution, straightness, and reproducibility of stretched DNA deposited in arrays onto elastomeric surfaces and thin membranes.
View Article and Find Full Text PDFWith the recent advances in electron microscopy (EM), computation, and nanofabrication, the original idea of reading DNA sequence directly from an image can now be tested. One approach is to develop heavy atom labels that can provide the contrast required for EM imaging. While evaluating tentative labels for the respective nucleobases in synthetic oligodeoxynucleotides (oligos), we developed a streamlined CE protocol to assess the label stability, reactivity, and selectivity.
View Article and Find Full Text PDFA major type of unwanted cells that accumulate in aging are anergic cytotoxic T cells. These cells often have virus-specific T cell receptors, as well as other surface markers that distinguish them from their youthful counterparts, and they are thought to play a major role in the decline of the immune system with age. Here we consider two surface markers thought to define these cells in mice, CD8 and Killer cell lectin-like receptor G1 (KLRG1), and a means we developed to remove these cells from the blood of aged C57BL/6 mice.
View Article and Find Full Text PDFAbstract A major driver of aging is catabolic insufficiency, the inability of our bodies to break down certain substances that accumulate slowly throughout the life span. Even though substance buildup is harmless while we are young, by old age the accumulations can reach a toxic threshold and cause disease. This includes some of the most prevalent diseases in old age-atherosclerosis and macular degeneration.
View Article and Find Full Text PDFCurrently, the aging research field lacks consensus in its focus and methodology. Foundational principles, such as the evolutionary origins and physiological definition of aging, remain controversial. The aim of this paper is to resolve these issues.
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