Direct measurement of lysosomal Ca²⁺ can be achieved by utilizing dextran conjugated Ca²⁺ indicators. Dextran Ca²⁺ indicators are cell-impermeable and must be taken up by cells through endocytosis. These endocytic vesicles travel into the cytosol and eventually fuse with lysosomes. Once fused, lysosomal Ca²⁺ movement can be detected by these dextran Ca²⁺ indicators.

For a list of AAT Bioquest dextran Ca²⁺ indicators conjugated with 3000 and 10,000 MW Dextran click here.