I-motif DNA of 0.2 ppm. I-motif DNA i-motif DNA is a type of deoxyribonucleic acid, discovered in 2018, that is found in the nuclei of human cells. An abbreviation of intercalated motif, the four-strand i-motif is unlike the iconic double helix DNA. I-motifs are four-stranded quadruplex structures formed by cytosine-rich DNA, similar to the G-quadruplex structures that guanine-rich DNA forms. C-rich DNA regions are common in gene regulation portions of the genome. Recently, i-motifs were discovered in human cells and were shown to play a role in cell reproduction. I-motifs have potential applications in nanotechnology and nanomedicine due to their unique pH
Single-cell DNA template strand sequencing cellular processes. Briefly, pulse-chase assays allow researchers to track radioactively labelled molecules in the cell. In experiments used to study non-random chromosome assortment, stem cells are labeled or "pulsed" with a nucleotide analog that is incorporated in the replicated DNA strands. This allows the nascent stands to be tracked through many rounds of replication. Unfortunately, this method is found to have poor resolution as it can only be observed at the chromatid level. CO-FISH, or strand-specific fluorescence "in situ" hybridization, facilitates strand-specific targeting of DNA with fluorescently-tagged probes. It exploits the uniform orientation of major satellites relative to the direction