Abstract: The present invention relates to methods of isolating and enriching mesenchymal stem cells (MSCs) comprising treating a tissue sample comprising cells and extracellular matrix with an amount of a collagenase that is sufficient to free MSCs from the extracellular matrix in a liquid medium and then isolating a fraction of the medium containing MSCs. The isolated MSCs can be isolated in surprisingly large numbers such that the fraction can have immediate use in a number of clinical contexts. This represents an advance of prior art techniques that either require the pooling of large volumes of sample tissues from different sources or require MSCs to be expanded in culture. The invention therefore further concerns the clinical use of cells isolated according to the methods of the first aspect of the invention.