Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.


Logo for

PNAS 102 (14): 5050-5055

Copyright © 2005 by the National Academy of Sciences.


A long-range attraction between aggregating 3T3 cells mediated by near-infrared light scattering

Guenter Albrecht-Buehler *

Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611

Edited by Judah Folkman, Harvard Medical School, Boston, MA, and approved February 25, 2005

Received for publication October 19, 2004.

Abstract: At what range can a mammalian cell sense the presence of another cell and through what medium? To approach these questions, the formation of aggregates of a 3T3 cell variant (3T3x cells) grown on solid substrates was studied. Each of the aggregates consisted of cells that, at the time of their seeding, were single and located randomly. Yet somehow they seemed to detect each other within a certain range (Ra) and move together to form aggregates. The article describes a simple assay to measure the value of Ra. When applied to 3T3x cells with altered intensities of near-infrared light scattering (Isc) the assay showed that (i) Ra was much larger than one cell diameter, and (ii) Ra was directly related to Isc. The results suggest that near-infrared light scattering by the cells mediate a long-range attraction between them, which does not require physical contact and enables them to detect each other's presence.

Key Words: aggregation • cell sorting

Author contributions: G.A.-B. designed research, performed research, contributed new reagents/analytic tools, analyzed data, wrote the paper, and wrote attached software.

This paper was submitted directly (Track II) to the PNAS office.

Freely available online through the PNAS open access option.

* E-mail: g-buehler{at}

© 2005 by The National Academy of Sciences of the USA

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882