Fig. 7From: Penetration of CdSe/ZnS quantum dots into differentiated vs undifferentiated Caco-2 cellsDistances of QD-COOH to the cytoplasmic membrane. Histograms of distances between the membrane and QD-COOH in undifferentiated cells (a) and in differentiated cells (b) using a concentration of 45 µg cadmium ml−1. Xc represents the peak position and standard deviation of the Gauss fitBack to article page