Archive for September, 2011
You may have heard about Fluorescent Cell Barcoding, a flow cytometry technique that allows researchers to answer a larger number of questions with the same amount of antibody, as compared to standard flow cytometry experiments [1,2]. We’ve prepared a few resources to help you learn about, perform, and analyze barcoding experiments.
How does barcoding work? In the barcoding step, samples treated under different stimulation conditions are labeled with concentrations of dye that increase at a defined interval. The use of this dye to barcode effectively means that one cytometer channel is taken up for this code. The distinctly stimulated and labeled samples are then combined into one tube and stained with antibodies against targets of interest. This single tube is then run on a flow cytometer and data are collected for analysis. The most common approach is to barcode different stimulation conditions; however, barcoding can be applied to any distinct populations, such as patient samples or different time points of a stimulation condition.
Dataset #8414: Human Cord Blood – HSC isolation
Hematopoietic Stem Cells (HSCs) give rise to all blood lineages and are capable of self-renewal. Clinically, HSC transplantation is under investigation for the treatment of diseases of the blood and bone marrow, including cancer, where a patient’s blood cells are wiped out and replaced with healthy cells that arise from transplanted donor HSCs. Transplant studies in mice have shown that only a few of these cells are necessary to repopulate the entire hematopoietic system.
Human umbilical cord blood is a rich source of stem cells, including HSCs. However, a variety of other cell types populate cord blood and must be removed from HSC preparations used for transplantation. Multipotent progenitor cells (MPPs) are one such population. Derived from HSCs, MPPs give rise to multiple lineages and are present in significant quantities in cord blood, though they are limited in their capacity for self-renewal. Purification of HSCs can be achieved by staining and running cord blood through a FACS sorter and isolating cells with a Lin-CD34+CD38-CD90+CD45RA- surface signature (as defined by Park, Majeti, and Weissman). MPPs can be quantified or isolated by their Lin-CD34+CD38-CD90-CD45RA- signature.
If you would like to try your hand at analyzing HSC enrichment data on Cytobank, we have made available an HSC dataset provided to us by scientists at BD Biosciences. You can find a tutorial to guide your analysis on our documentation site. (more…)