These are fixed, permeabilized, and fluorescently-stained muntjac skin fibroblasts in either interphase or a phase of mitosis. The phases, going from top left to bottom right, are: interphase, prophase, metaphase, anaphase, and telophase.
During interphase, a eukaryotic cell multiplies its inventory of organelles and replicates its DNA (pink), growing in size.1 Next, mitosis is activated and the cell enters prophase, during which its replicated DNA is supercoiled into chromosomes comprised of identical, paired sister chromatids. Eventually, the cell’s nuclear envelope disintegrates, and special microtubules (green) linking the kinetochores of chromatids to the cell’s poles develop. The cell then enters metaphase, during which the centromeres of its chromosomes become aligned in a plane at its equator. After passing a key mitotic checkpoint, the cell enters anaphase, during which the paired sister chromatids separate and are pulled to opposite poles. Finally, in telophase, nuclear envelopes and nucleoli re-form around each pole’s collection of DNA, chromatids uncoil back into chromatin, and the cell divides in two. Each daughter cell is at the start of interphase, and the cell cycle repeats.2
Alexa Fluor® 350 phalloidin labeled actin filaments (blue) throughout each cell. An anti-α-tubulin antibody prelabeled with the Zenon® Alexa Fluor® 488 Mouse IgG1 Labeling Kit marked microtubules (green), revealing their role in mitosis. The anti–Cdc6 peptide antibody prelabeled with the Zenon® Alexa Fluor® 647 Mouse IgG1 Labeling Kit stained DNA (pink) in both chromatin and chromosomes.
References: (1) Clare O’Connor, Nature; (2) D. Sadava et al., Nature. Photos: courtesy of the Life Technologies Corporation.
“I usually take a walk after breakfast, write for three hours, have lunch and read in the afternoon. Demons don’t like fresh air - they prefer it if you stay in bed with cold feet; for a person who is as chaotic as me, who struggles to be in control, it is an absolute necessity to follow these rules and routines. If I let myself go, nothing will get done.”
University of California, Berkeley researchers have developed a device that uses wireless signals to provide real-time, non-invasive diagnoses of brain swelling or bleeding.
The device analyzes data from low energy, electromagnetic waves, similar to the kind used to transmit radio and mobile signals. It could potentially become a cost-effective tool for medical diagnostics and to triage injuries in areas where access to medical care, especially medical imaging, is limited.
The researchers tested a prototype in a small-scale pilot study of healthy adults and brain trauma patients admitted to a military hospital for the Mexican Army. The results from the healthy patients were clearly distinguishable from those with brain damage, and data for bleeding was distinct from those for swelling.
“There are large populations in Mexico and the world that do not have adequate access to advanced medical imaging, either because it is too costly or the facilities are far away,” said César A. González, a professor at the Instituto Politécnico Nacional, Escuela Superior de Medicina (National Polytechnic Institute’s Superior School of Medicine) in Mexico.
“This technology is inexpensive, it can be used in economically disadvantaged parts of the world and in rural areas that lack industrial infrastructure, and it may substantially reduce the cost and change the paradigm of medical diagnostics. We have also shown that the technology could be combined with cell phones for remote diagnostics.”
Boris Rubinsky, Professor of the Graduate School at UC Berkeley’s Department of Mechanical Engineering, who led the research team, noted that symptoms of serious head injuries and brain damage are not always immediately obvious, and for treatment, time is of the essence. For example, the administration of clot-busting medication for certain types of strokes must be given within three hours of the onset of symptoms.