In 1665, Robert Hooke peered down his microscope at a piece of cork and iscovered little boxes that reminded him of rooms in a monastery. Being the first scientist to describe cells,
Hooke would be amazed by biology’s next
mega-project: a scheme to individually
capture and scrutinize millions of cells
using the most powerful tools in modern
genomics and cell biology.
The objective is to construct the
first comprehensive “cell atlas,” or map
of human cells, a technological marvel
that should comprehensively reveal, for
the first time, what human bodies are
actually made of and provide scientists a
sophisticated new model of biology that
could speed the search for drugs.
To perform the task of cataloguing
the 37. 2 trillion cells of the human body,
an international consortium of scientists
from the U.S., U.K., Sweden, Israel, the
Netherlands, and Japan is being assembled to assign each a molecular signature
and also give each type a zip code in the
three-dimensional space of our bodies.
“We will see some things that we
expect, things we know to exist, but
I’m sure there will be completely novel
things,” says Mike Stubbington, head of
the cell atlas team at the Sanger Insti-
tute in the U.K. “I think there will be
Previous attempts at describing cells,
from the hairy neurons that populate the
brain and spinal cord to the glutinous
fat cells of the skin, suggest there are
about 300 variations in total. But the
true figure is undoubtedly larger. Analyz-
ing molecular differences between cells
has already revealed, for example, two
new types of retinal cells that escaped
decades of investigation of the eye; a cell
that forms the first line of defense against
pathogens and makes up four in every
10,000 blood cells; and a newly spot-
ted immune cell that uniquely produces
a steroid that appears to suppress the
Three technologies are coming
together to make this new type of mapping possible. The first is known as “
cellular microfluidics.” Individual cells are
separated, tagged with tiny beads, and
manipulated in droplets of oil that are
shunted like cars down the narrow, one-way streets of artificial capillaries etched
into a tiny chip, so they can be corralled,
cracked open, and studied one by one.
The second is the ability to identify the genes active in single cells by
decoding them in superfast and efficient
sequencing machines at a cost of just a
few cents per cell. One scientist can now
process 10,000 cells in a single day.
The third technology uses novel
labeling and staining techniques that can
locate each type of cell—on the basis of
its gene activity—at a specific zip code in
a human organ or tissue.
Behind the cell atlas are big-science
powerhouses including Britain’s Sanger
Institute, the Broad Institute of MIT and
Harvard, and a new “Biohub” in California funded by Facebook CEO Mark
Zuckerberg. In September Zuckerberg
and his wife, Priscilla Chan, made the cell
atlas the inaugural target of a $3 billion
donation to medical research.
Fig. 1 Robert Hooke’s drawing of cork,
as seen through a microscope (1665).
Fig. 2 Sperm containing a homunculus
(Nicholas Hartsoeker, 1695).
Fig. 3 Daguerreotypes of blood from
humans, camels, and toads (A. Donné,
Fig. 4 Plant cells (J. M. Schleiden,
Fig. 5 Sketches of animal cells
(Theodor Schwann, 1839).
Fig. 6 A nerve (A. von Kolliker, 1852).