What is the minimum amount of starting material that can be used with the RNeasy Plus Micro and AllPrep DNA/RNA Micro Kit?
FAQ ID -1750

In our labs, we were able to purify RNA using the RNeasy Plus Micro Kit, or DNA/RNA using the AllPrep DNA/RNA Micro Kit at single cell level. However, generally we do not recommend purification from fewer than 10–20 cells, due to stochastics related to transcript copy numbers present in a single cell.

For example, if an RNA transcript is present at only 1 copy per cell, recovery from a purification using e.g., 10 cells or less, would be less than 1 transcript copy per microliter, given the recommended elution volume of 14 µl.