3D quantitative phase imaging via the transport of intensity equation: applications for studying red blood cells

Quantitative phase imaging (QPI) is a versatile, label-free technique for investigating the morphological and biophysical properties of biological cells. Here, we used 3D QPI to study the behavior of human red blood cells (RBCs) across a saline gradient from 1% to 0%. RBCs are osmotic-sensitive, and their phase profiles provide important measures of membrane integrity, shape transitions, and lumen hemolysis. Deducing phase alterations across each concentration allowed us to quantify the osmotic impacts on RBC morphology and assess the corresponding biophysical changes. Other studies on osmotic shock contributed to understanding the behavior of RBCs in hypotonic environments and their applications in hematological and biomedical fields.