Sulforhodamine 101 Explained

Sulforhodamine 101 (SR101) is a red fluorescent dye. In neurophysiological experiments which comprise calcium imaging methods, it can be used for a counterstaining of astrocytes to be able to analyze data from neurons separately.^[1] However, in addition to labeling astrocytes, SR101 labels myelinating oligodendrocytes.^[2] SR101 has been reported to affect excitability of neurons and should therefore be used with caution.^[3]

A sulfonyl chloride derivative of sulforhodamine 101, known as Texas Red, is used for conjugation to a number of functional groups, especially primary amines.

Notes and References

1. Nimmerjahn, A. . Kirchhoff, F. . Kerr, J.N. . Helmchen, F.. Sulforhodamine 101 as a specific marker of astroglia in the neocortex in vivo . . 2004 . 1 . 1 . 31–7 . 15782150 . 10.1038/nmeth706. 2073853 .
2. Hill, R.A. . Grutzendler, J.. In vivo imaging of oligodendrocytes with sulforhodamine 101 . . 2014 . 11 . 11 . 1081–1082 . 25357236 . 10.1038/nmeth.3140 . 4539948.
3. 4 . Kang, J. . Kang N. . Yu, Y. . Zhang, J. . Petersen, N. . Tian G.-F. . Nedergaard, M. . Sulforhodamine 101 induces long-term potentiation of intrinsic excitability and synaptic efficacy in hippocampal CA1 pyramidal neurons . . 2010 . 169 . 4 . 1601–1609 . 20600669 . 10.1016/j.neuroscience.2010.06.020 . 2918738 .