Hi guys. Recently I had read an article, and I’m quite puzzled about the results of the quantifications of immunostaining. How did the percentage of immunoreactive positive area was bigger than 100%? Does anyone know how to explain? Thanks a lot for your answers! Here are the screenshots of the results and methods about this article.
Zhou Ying You are absolutely right. Their definition of IR is literally "the number of positive pixels divided by the sum of positive+negative pixels". Using this definition, one mathematically CANNOT produce value higher than 100%. Their legend for Fig. 1B suggests that they have made a mistake in creating the graph, since they are talking about very reasonaly values, e.g. 18%, 11%, 27%. What happened in the naming of Y axis and the numbers on Y axis, is a mystery. But you are absolutely correct, this HAS TO BE corrected. If you are reviwing this article, point it out to them. If you just saw this article somewhere, write to the editor of the journal and alert him about this mysterios numbering on Y axis, since it is NOT CORRECT.
Also, their description of the methods for quantitation is borderline nonsensical. Always a bad sign.