Secondary Speckle Sensing Microscopy (S3M). The difference between an infected red blood cell (top) and a healthy cell (bottom) is revealed by S3M, in part, by considering the dynamics of the correlation value (CV). CV indicates the similarity between two patterns. 1,000 CVs are calculated from pairs of consecutive speckles acquired in 1 second. As shown in the chart at right, the CV oscillation range for the infected cell (top, 0.36) is almost three times larger than that of the healthy red blood cell (bottom, 0.13). In the top left image of the infected cell a parasitic life-cycle stage of malaria, called “trophozoite,” can be seen (arrow). Credit: Dan Cojoc, Materials Technology Institute, National Research Council, Italy.