I would like to ask for expert advice here about single Cell RNA-seq to study differential gene expressions in treated vs. untreated groups especially about sample size. According to the nature rev genetics paper by Shapiro 2013, he recommends a minimal of 50 cells are needed to reduce the error for quantitative transcriptomic analysis. Then I come across other papers / methods such as EdgeR, Scotty which seems to suggest smaller size of 12. Of course, provided cost and sample availability is NOT a concern I would just go for '50' but I'm not sure if it is safe at all to just sequence 12 cells and hope for statistically meaningful results.
Next is about validation - I've seen methods such as single cell QPCR, digital PCR, single cell nano string. Which method would be suitable for validation, and again how many single cells would you pick to validate? Thank you very much in advance for your helpful advice.