Assessment of biological activity in RAW 264.7 cell line stimulated with lipopolysaccharide using dynamic laser speckle

Dynamic laser speckle (DLS) technique or biospeckle is a noninvasive approach that can sensitively monitor the dynamics of a biological material such as the metabolism of cells. In turn, stimulation of cell activity is widely used in microbiology: it can be done by means of many agents, such as lipopolysaccharide (LPS), which is the most common component within the cell wall of Gram-negative bacteria, and it has been extensively used in in vitro models studying inflammation. The main challenge is to monitor the change of behavior inside the cells during their stimulation. This work tested the viability of the BSL to monitor the change in the metabolism of RAW cells when LPS is applied. The results show different answers of cells to distinct concentrations of LPS, and the inflammatory process promoted by the LPS could be best distinguished from the RAW cells alone in a concentration of 10 ng/mL. This proved the ability of the DLS to monitor the agent stimulus.