Hi. I would like to look into the effect of a compound on treated and untreated cells. For my negative controls (comprising of untreated cells), upon staining with antibody, I get a range of 1 to 2% antigen positive cells. My doubt is, whether such a 1 to 2% reading normal as my conceptual is that negative controls should not have any reading as it did not contain the expression. Thank you.
negative control readings
Posted 22 June 2018 - 09:30 AM
It honestly depends on your target and your experimental conditions. Negative controls are not always completely negative in signal but rather should represent "background" in a system that is known to either be completely missing or significantly lower than your experimental conditions. For example, a negative control for an antibody can be siRNA mediated knockdown of the target. You are not going to completely lose all signal as knockdown is not 100% but there should be enough of a reduction in signal to be able to identify a difference in the control non-treated. If you know for certain that the target is completely absent, then what you are getting is background and can be used to set a limit or gate your analysis as negative results for all other samples.