Mesenchymal stem/stromal cells (MSCs) are widely reported to be multipotent precursors present in the stromal fraction of many adult tissues. For this reason, they have been the subject of intense investigation, especially in the context of regenerative medicine. However, their anatomical location, in situ phenotype, and functional properties are one of the most controversial and confusing areas in stem cell biology. Specifically, the use of adipose derived stem/stromal cells for orthopedic applications is widely disputed. Subcutaneous fat is an abundant and accessible source of heterogeneous stromal vascular fraction (SVF) cells that undoubtedly contains pre-cursor cells capable of differentiating into white adipocytes (pre-adipocytes), and possibly also progenitor cells capable of differentiating into other mesenchymal lineages, such as bone and cartilage. These latter cells are often described as multipotent adipose-derived stem cells from which “homogeneous” cultured lines are often derived. However the cell surface phenotype of these cultured cells is dramatically affected by cell culture. In addition, evidence of multi-lineage differentiation, and importantly, clinical translation potential amongst these tissue cultured “MSC” lines is weak, suggesting that populations that might reasonably be termed MSCs are rarer than previously appreciated. In an effort to discriminate between mesenchymal cells with potential stem cell properties and those that are more differentiated, we aim to use multicolour flow cytometry and single cell transcriptomics to survey the heterogeneity of mesenchymal cell populations present in adipose tissue. Preliminary flow cytometry studies have indeed revealed striking heterogeneity for a number of cell surface receptors. This heterogeneity suggests there are likely to be sub-populations with differing capacity to differentiate down various lineages. Using knowledge from these flow cytometric studies, we seek to further define tissue heterogeneity by utilising CITE-seq (Cellular Indexing of Transcriptomes and Epitopes by sequencing), to simultaneously characterise surface proteins and transcriptomes at the single cell level (scRNAseq).