Multivariate analysis of E. coli with various treatments, where red triangles are autoclaved cells, blue diamonds are sonicated cells, and green dots are live cells. Here, the samples were washed and resuspended in distilled water and analyzed with fs-LIBS. (a) Three-dimensional score plot of first three principal components from PCA. (b) Calibration variance (blue) and validation variance (red) plot as function of principal components. (c) Line plots of X-loadings for the first three principal components. (d) SIMCA approach to see if new test samples belong to an already existing group of similar samples. It displays the orthogonal distances from new samples to two different classes (autoclaved and live cells), where red triangles are autoclaved cells, green circles are live cells, and black squares are test samples (TA-1 and TA-2 are test samples of autoclaved, TS-1 and TS-2 are test samples of sonicated, and TL-1 and TL-2 are test samples of live cells).