  Raman microscopy is a powerful method combining non-invasiveness with no
special sample preparation. Because of this remarkable simplicity, it has been
widely exploited in many fields, ranging from life and materials sciences, to
engineering. Notoriously, due to the required imaging speeds for bio-imaging,
it has remained a challenge how to use this technique for dynamic and
large-scale imaging. Recently, compressive Raman has been put forward, allowing
for fast imaging, therefore solving the issue of speed. Yet, due to the need of
strong a priori information of the species forming the hyperspectrum, it has
remained elusive how to apply this technique for microspectroscopy of (dynamic)
biological tissues. Combining an original spectral under-sampling measurement
technique with matrix completion framework for reconstruction, we demonstrate
fast and inexpensive label-free molecular imaging of biological specimens
(brain tissues and single cells). Therefore, our results open interesting
perspectives for clinical and cell biology applications using the much faster
compressive Raman framework.
