SEM observation of the live morphology of human red blood cells under high vacuum conditions using a novel RTIL

Abstract

In this study, we succeed in visualizing a ‘living’ morphology of red blood cells (RBCs) by a rapid and simple scanning electron microscope (SEM) pretreatment using a hydrophilic room temperature ionic liquid (RTIL) with asymmetrical structure. The conventional pretreatment induces size shrinkage of the cells, and the diameter observed in an SEM (less than 6 µm) was smaller than that in an optical microscope (8 µm). Though RBCs are well‐known to be easily deformed with the environmental conditions, the cells did not show the deformation when they were pretreated with our RTILs. Since the chemical structure of our RTIL resembles a ‘choline’, which is a typical bioactive material, and has biocompatibilities, they may make it avoid from the deformation of RBCs. In fact, only immersing RBCs, our novel RTIL can provide a clear SEM image without size shrinkage and deformation. Interestingly, the obtained SEM image shows 8 µm in the diameter, almost same size as that in optical microscope. Therefore, this method is expected for novel SEM pretreatment for various biological samples observation as ‘living’ matter. Copyright © 2014 John Wiley & Sons, Ltd.