The construction of a low affinity Ca²⁺-probe that locates to the cell cortex and cell surface wrinkles, is described called. EPIC3 (ezrin-protein indicator of Ca²⁺). The novel probe is a fusion of CEPIA3 with ezrin, and is used in combination with a Ca²⁺-insensitive probe, ezrin-mCherry, both of which locate at the cell cortex. EPIC3 was used to monitor the effect of Ca²⁺ influx on intra-wrinkle Ca²⁺ in the macrophage cell line, RAW 264.7. During experimentally–induced Ca²⁺influx, EPIC3 reported Ca²⁺ concentrations at the cell cortex in the region of 30−50 μM, with peak locations towards the tips of wrinkles reaching 80 μM. These concentrations were associated with cleavage of ezrin (a substrate for the Ca²⁺ activated protease calpain-1) and released the C-terminal fluors. The cortical Ca²⁺ levels, restricted to near the site of phagocytic cup formation and pseudopodia extension during phagocytosis also reached high levels (50−80 μM) during phagocytosis. As phagocytosis was completed, hotspots of Ca²⁺ near the phagosome were also observed.

位于细胞皮层和细胞表面皱纹的低亲和力 Ca ²⁺探针的构建被称为。EPIC3（É zrin- p rotein我的ndicator Ç一个²⁺）。新型探针是 CEPIA3 与 ezrin 的融合，并与 Ca ^{2+ 不}敏感探针 ezrin-mCherry结合使用，两者均位于细胞皮层。EPIC3 用于监测 Ca ²⁺流入对巨噬细胞系 RAW 264.7 中皱纹内 Ca ²⁺的影响。在实验诱导的 Ca ²⁺流入期间，EPIC3 报告了 Ca ²⁺细胞皮层的浓度在 30-50 μM 范围内，皱纹尖端的峰值位置达到 80 μM。这些浓度与 ezrin（Ca ²⁺活化蛋白酶钙蛋白酶-1的底物）的裂解有关，并释放 C 端荧光。皮质Ca ²⁺水平仅限于吞噬过程中吞噬杯形成和伪足延伸的部位附近，在吞噬过程中也达到高水平（50-80 μM）。随着吞噬作用的完成，还观察到吞噬体附近的Ca ²⁺热点。