Images of bull sperm (one with and one
without tail) at an x-ray wavelength of 4.28 nanometers
(billionths of a meter). From such images
obtained at several wavelengths, the protein (center)
and DNA (right) distributions were determined. From X. Zhang, R.
Balhorn, J. Mazrimas and J. Kirz, J. Structural Biology 116, 335
(1996). Thanks to Janos Kirz and Chris Jacobsen of the State University of New York at
Stony Brook for supplying the figure and
the caption text.
In what is believed to be the smallest focused beam of light yet created on Earth,
Janos Kirz, Chris Jacobsen, and their colleagues at the State University of New York at
Stony Brook produced an x-ray beam with a diameter of just 50 nanometers (billionths of a meter)at the
Brookhaven National Synchrotron Light Source in New York.
Their beam is an example of an "x-ray microprobe,"
which can be used to perform x-ray studies on tiny samples or objects with miniscule features.
The researchers used this beam to obtain the first-ever images showing the distribution of DNA and protein in sperm from bulls and other mammals.
This research was described at the 1997 March Meeting of the American
Physical Society in Kansas City, Missouri.
