These colorful fractions were obtained upon purifying a synthetic small-molecule through flash column chromatography. Though most of these were impurities (bright colors in organic chemistry is usually not a great sign), it served as a reminder to appreciate the beauty in the mundane and seemingly unimportant. Contributed by Carmen Sivakumaren, a graduate student in the Biological and Biomedical Sciences Program at Harvard Medical School.   Continue reading Spectrum


The adaptation of the opportunistic human pathogen Pseudomonas aeruginosa often produces phenotypic diversity. Here, mutants isolated from a genetic screen show notable differences in phenotype: the production of pigments, size, shape, and texture. The blue-green pigmentation seen in some mutants results from the production of pyocyanin, an excreted toxin that kills other microbes and mammalian cells. Whereas, the brown pigmentation is caused by the exocellular pigment, pyomelanin, which … Continue reading Pseudomonads

Neuronal Diversity of the Axolotl Brain

What you’re seeing is the brain of an axolotl, an organism known for its ability to regenerate many organs including the limb, heart, and spinal cord. The different colors (blue, green, red) represent some of the neuronal cell types present within the brain. Incredibly, when this region of the brain is injured, the brain regenerates with fidelity, and all of these cell types are remade. … Continue reading Neuronal Diversity of the Axolotl Brain


Gene therapy is an approach to treating genetic diseases by re-introducing a functional copy of a gene into cells to replace the mutated, disease-causing gene. To get these genes into the cells, scientists create a vector by packaging the DNA encoding the correct gene into the outer shell–called the capsid–of a virus. A vector retains the ability of the virus to enter human cells and … Continue reading Masquerade

The Blood Flow Border Patrol

The intricate network of blood microcirculation in the human body is a closed and complex one. The hierarchy of blood flow in the human body takes blood from the heart to deep organs systems, through arteries that branch out into smaller arterioles and later into microscopic capillaries. Presented here is a pseudo colored montage of images taken and combined from different magnifications that represent a … Continue reading The Blood Flow Border Patrol


Zebrabow embryos express random combinations of red, green, and blue fluorescent proteins, revealing a spectrum of unique hues. These same hues can be used to ‘barcode’ individual stem cells to track their birth and contribution to tissues as the embryo grows–all cells of the same hue were produced from one stem cell’s divisions. The Zebrabow system allows for long-term tissue lineage analysis, because the fluorescent proteins will … Continue reading Zebrabow

A Sight For Sore Eyes

  Have you ever experienced itchy, watery eyes as a result of seasonal allergies? The objects in this picture are to blame. This microscope image shows conjunctival tissue from an eye in the presence of a single mast cell. Mast cells are important regulators of the immune system. Upon invasion of the eye with foreign objects, such as allergens, the mast cell is recruited to … Continue reading A Sight For Sore Eyes

Holding the Fort Down

And how! Depicted here are intricate collagen fibers, the structural glue and the most abundant protein in the mammalian body. Collagen proteins occupy the extracellular space in connective tissues, and form fibers that provide the physical scaffold for holding and strengthening several tissues in the body including bones, ligaments, tendons, skin, and the cornea. With several different classes of this protein defined to date, type … Continue reading Holding the Fort Down

Branched synaptic arbor in fillet

The Drosophila neuromuscular junction is a beautiful and yet powerful model synapse for in vivo studies of development, physiology, cell biology and plasticity. This illustration by Saskia Van Vactor shows a field of ventral longitudinal body wall muscles in red, as if stained with phalloidin to highlight filamentous actin, the main protein building block of muscle. Against this background, several branches of intersegmental nerve extend … Continue reading Branched synaptic arbor in fillet