We tested several alternative strategies, to try to prevent this effect, including a carbon coating, but none gave satisfactory SEM observations of the cell surface and final visualization of the chimeric viral particles. Nevertheless, our CSEMTEM method provided the first observation of a chimeric flavivirus being released as an individual particle in small exocytosis vesicles. These results are consistent with recent gene silencing experiments showing that host cell exocytosis factors, such as Sec3p and EXO70, are essential for DENV egression or secretion. This is also consistent with the maturation of flavivirus particles in the Golgi compartment. Hepacivirus and pestivirus virions are infectious immediately, or at least very shortly after their envelopment, but flavivirus particles remain immature until the acid-induced rearrangement of their envelope E protein and the furin-mediated cleavage of their prM protein have occurred in the late Golgi compartment. The scarcity of virus-coated cells at any given time suggests that this exocytosis is probably a very short-lived process. Moreover, the presence of large numbers of chimeric flavivirus particles evenly distributed over a large surface of these rare cells suggests that this mechanism is driven by many exocytosis vesicles being 
generated at the same time in a given cell. This suggests that the release of the chimeric virions occurs via a regulated exocytosis that may also account for the absence of morphological changes or obvious cytotoxicity in the virus-coated cells studied by SEM. Our data obtained with microscopic approaches may provide new insight into basic flavivirus/cell interactions and may facilitate the definition of targets for the development of preventive and therapeutic strategies for combating infections due to these viruses. However, it will be necessary to confirm these observations with wild-type flavivirus strains. It will be also necessary to further investigate this phenomenon by confirming our morphological data with Salvianolic-acid-B biological experiments. Nevertheless, our findings suggest that CSEMTEM is a potentially useful new Tetrahydroberberine correlative microscopy method for analyzing the intracellular ultrastructure of cells presenting particular surface modifications, which could be applied to the study of other important biological processes. Although limited by technical constraints, CSEMTEM will be particularly useful as compared to CLEM to study virus/cell interactions, as fluorescence methods do not reveal detailed information about the structure of viruses. Viruses can be visualized as small spots on fluorescence microscopy, but the resolution of this technique is too low to determine whether these fluorescent spots correspond to assembled virions or aggregated viral proteins. Thus, CSEMTEM will remain a useful technique for visualizing structured virions at the surface of infected cells and investigate the intracellular ultrastructure of virion-producing cells. Obesity is a public health problem that has greatly increased over the last decade. It is accompanied by a series of diseases such as type 2 diabetes mellitus, cardiovascular diseases, and increased visceral fat, among others, which characterize the metabolic syndrome. It is also characterized by an increased size and number of adipocytes.