Limiting-Dilution Transplantation Assays in Mammary Stem Cell Studies
Mammary reconstitution assays can be used to measure the stem cell frequency within an epithelial population by transplanting increasingly diluted single-cell preparations of the population of interest. There are fundamental steps in the single-cell isolation protocol which are directly related to the number of single epithelial cells obtained. Once single-cell suspensions have been obtained, serial dilutions are prepared and transplanted into the cleared fat pads of the host mice. After 8–10 weeks, the transplanted fat pads are reevaluated for the presence of epithelial outgrowths. Based on the frequency of no outgrowth for each one of the transplanted dilutions, it is possible to estimate the frequency of mammary repopulating cells present in a given cell population. Here, we give details on how to carry out all these steps.
Key wordsCell isolation Differential centrifugation Cleared fat-pad Transplantation Outgrowth Wholemount
This work was supported by a predoctoral fellowship to RFG from the Department of Defense Breast Cancer Research Program (DAMD 17-03-1-0594), grants from the same institution to COS (DAMD 17-00-1-0227 and DAMD 17-00-1-0306), a grant to BEW from the National Cancer Institute (CA 8424306), and a grant to MHBH funded by the National Institute of Environmental Health Sciences and the National Cancer Institute (U01 ES012801).
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