Arjun Raj

faculty photo
Assistant Professor of Bioengineering
Department: Bioengineering

Contact information
Office: 111 Hayden Hall
Mail: 210 S. 33rd Street
Skirkanich Hall, Room 240
Philadelphia, PA 19104
Office: 215-821-7394
University of California, Berkeley, 2000.
New York University, 2006.
Permanent link

Description of Research Expertise

Research Interests: RNA systems biology, particular as related to non-coding RNAs and cancer biology.

Keywords: RNA, systems biology, cancer, non-coding RNAs

Research Details:
The Raj lab studies the biology of single cells. The primary motivation for studying biological processes on a cell-by-cell basis is the fact that even genetically identical cells can behave very differently. Many of these differences arise as a consequence of the developmental process, whereby some cells are directed to become, for example, liver cells while others become skin cells. We aim to understand these differences at the molecular level. One of our primary experimental tools is a method we have developed for detecting individual RNA molecules via fluorescence microscopy, yielding very precise, quantitative data about RNA abundance and localization within single cells. One application of this method is the visualization of non-coding RNAs. Recently, researchers have made the exciting discovery that much of the genetic material that was previously thought to be “junk” DNA is actually converted into RNA molecules, and some of these non-coding RNA molecules appear to have direct functional roles in development. We are directly visualizing and localizing these molecules in their cellular context to decipher the mechanisms by which they operate, including potential roles in stem cell differentiation. Another area in which cellular heterogeneity is important is cancer. We are producing RNA expression maps throughout tumor sections at single cell resolution to measure spatial variation in expression during tumor formation and development. We anticipate that such studies will lead to new diagnostic tools as well as a deeper understanding of cancer biology.

Rotation Projects: Please contact Arjun for more details.

Lab Personnel:
Marshall Levesque (Graduate student, Bioengineering)
Hedia Maamar (Postdoc)
Gautham Nair (Postdoc)

Selected Publications

Raj Arjun, Rifkin Scott A, Andersen Erik, van Oudenaarden Alexander: Variability in gene expression underlies incomplete penetrance. Nature 463(7283): 913-8, Feb 2010.

Khalil Ahmad M, Guttman Mitchell, Huarte Maite, Garber Manuel, Raj Arjun, Rivea Morales Dianali, Thomas Kelly, Presser Aviva, Bernstein Bradley E, van Oudenaarden Alexander, Regev Aviv, Lander Eric S, Rinn John L: Many human large intergenic noncoding RNAs associate with chromatin-modifying complexes and affect gene expression. Proceedings of the National Academy of Sciences of the United States of America 106(28): 11667-72, Jul 2009.

Raj Arjun, van Oudenaarden Alexander: Single-molecule approaches to stochastic gene expression. Annual review of biophysics 38: 255-70, 2009.

Raj Arjun, van Oudenaarden Alexander: Nature, nurture, or chance: stochastic gene expression and its consequences. Cell 135(2): 216-26, Oct 2008.

Raj Arjun, van den Bogaard Patrick, Rifkin Scott A, van Oudenaarden Alexander, Tyagi Sanjay: Imaging individual mRNA molecules using multiple singly labeled probes. Nature methods 5(10): 877-9, Oct 2008.

Maamar Hédia, Raj Arjun, Dubnau David: Noise in gene expression determines cell fate in Bacillus subtilis. Science (New York, N.Y.) 317(5837): 526-9, Jul 2007.

Raj Arjun, Peskin Charles S, Tranchina Daniel, Vargas Diana Y, Tyagi Sanjay: Stochastic mRNA synthesis in mammalian cells. PLoS biology 4(10): e309, Oct 2006.

Raj Arjun, Peskin Charles S: The influence of chromosome flexibility on chromosome transport during anaphase A. Proceedings of the National Academy of Sciences of the United States of America 103(14): 5349-54, Apr 2006.

Vargas Diana Y, Raj Arjun, Marras Salvatore A E, Kramer Fred Russell, Tyagi Sanjay: Mechanism of mRNA transport in the nucleus. Proceedings of the National Academy of Sciences of the United States of America 102(47): 17008-13, Nov 2005.

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Last updated: 11/28/2011
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