Esya's Probes

We invented nanodevices that measure chemical signals.


Our nanodevices target specific organelles within live cells.

Calcium Ion, Chloride Ion, pH, Enzymatic Activity, pH & Calcium Ion, pH & Chloride Ion

Early Endosome, Late Endosome, Lysosome, Recycling Endosome, Golgi Apparatus

pH Sensor: Our pH sensors are DNA nanodevices that map pH levels accurately inside the organelles of live cells. The interior of lysosomes are acidic (~pH 4.8), and numerous diseases are characterized by changes in pH within the lysosome. Our DNA probes can help monitor pH Levels and responses to drug therapies non-invasively with a single test.

Calcium Ion Sensor: Our calcium ion sensors are DNA nanodevices that map calcium ion levels inside the organelles of live cells. Calcium ions regulate diverse cellular functions, initiate signaling cascades, and are released from different intracellular stores. Lysosomes were recently discovered to be "acidic calcium ion stores", and changes to the level of calcium in organelles can be an important predictor of disease.

Chloride Ion Sensor: Our chloride ion sensor can measure the chloride levels inside cells by detecting fluorescence changes that are correlated with the amount of chloride present. These probes have shown lysosomes contain high levels of chloride and, when lysosomal chloride levels are compromised, the function of the overall lysosome is impacted.

Dual Calcium Ion and pH Sensor: Our pH-correctable, fluorescent DNA-based reporter is targetable to specific organelles and can measure both calcium ion and pH by ratiometrically reporting lumenal values for both ions simultaneously. Without this technology, it is extremely challenging to quantitate lumenal calcium ion in the acidic calcium stores of the cell.

Dual Chloride and pH Sensor: Our dual chloride and pH sensor can chemically resolve lysosome subpopulations by quantitatively imaging pH and chloride simultaneously within the same lysosome. Results are provided with single-lysosome resolution in live cells – two-ion measurement (2-IM). 2-IM enables investigators to chemically resolve lysosomal populations, better understand the role of the lysosome in physiology and pathophysiology, assess lysosomal integrity, and quantify the efficacy of drugs that alleviate lysosomal dysfunction.

Dual Hypochlorous Acid and pH Sensor: Our fluorescent, DNA-based reporter can simultaneously image hypochlorous acid and pH quantitatively by targeting phagosomes in live cells and mapping the production of a specific ROS, such as HOCl. This sensor found that phagosomal acidification was gradual in macrophages and, when acidity reached a critical level, HOCl was released in a burst, revealing phagosome-lysosome fusion was essential for phagosome acidification and myeloperoxidase activity. 


Enzymatic Activity Sensor: Our chemical imaging strategy for selectively interrogating the activity of an enzyme confines the detection chemistry to a single designated organelle, enabling imaging of enzymatic cleavage exclusively within an organelle of interest. To date, competing strategies provided information only at the cellular level as they rely on either fluorescent protein expression in the cytoplasm or non-specific small molecule internalization and, thus, can only provide information at the cellular level and are unable to focus exclusively on a subcellular target.

© 2020 – Esya Labs