||A pair of Staphylococcus aureus have gone through 2 cell divisions,
producing a pair of tetrads. Cell division in this and other bacteria
can occur every 20 to 30 minutes. Elsewhere on this site, you can
learn about the dynamics of bacterial growth.
||This leukemia cell is tearing itself apart by a process called
apoptosis. You can find out more about this natural phenomenon of
programmed cell death in "Apoptosis: when a cell commits suicide".
||Ascorbic acid (vitamin C) was dissolved in ethanol and allowed
to recrystallize through evaporation. The crystal was photographed
between crossed polarizing filters. Other crystals are on exhibit
in "CRYSTALS alive!"
||This scanning electron micrograph shows the fine structure of a
blood clot. Platelets released from the circulation and exposed to
the air use fibrinogen from the blood plasma to spin a mesh of fibrin.
Learn how other cells defend us against infection in "OUCH!...
Anatomy of a Splinter".
||Escherichia coli (E.
coli ) are very common intestinal inhabitants.
Some can be dangerous in food and water supplies. Most newsworthy
are life-threatening infections from eating undercooked E. coli 0157
- contaminated hamburger. Before leaving
"CELLS alive!", learn how bacteria swim and how they grow.
||Scanning electron micrograph of human macrophage ingesting Streptococcus
pyogenes. The spherical cell riding piggy-back on the macrophage
is a lymphocyte, an important component in the immune response to
infection. Read about these cells' close association in Antibody Production.
||Scanning electron micrograph of human red blood cells. Red cells
get their red color from iron-rich hemoglobin which is responsible
for transporting oxygen throughout the body. These cells got THEIR
red color from Photoshop(R). See animated red cells in capillaries
in "OUCH!... Anatomy of a Splinter".
||Scanning electron micrograph of the common soil bacteria Pseudomonas
aeruginosa. These bacteria are actively motile in aqueous environments
but can attach to a submerged surface and grow into a sessile, slimy
colony called a "biofilm". Colorized gray scale image.
||Human neutrophils are white blood cells that serve as professional
phagocytes: their primary function is to eat and kill bacteria and
they arrive quickly at the site of a bacterial infection. This neutrophil,
ingesting Streptococcus pyogenes, was imaged in gray scale with phase
contrast optics and colorized. See neutrophils in action in "OUCH!... Anatomy of a Splinter".
||This human eosinophil was originally imaged in gray scale with
Nomarski DIC optics and a CCD camera, then colorized using Adobe
Photoshop(R). Eosinophils are important in combatting parasitic diseases
and people with those diseases and allergies generally have elevated
eosinophil counts. See Allergies