New fluorescent sensors help scientists monitor acidity changes inside cancer cells

Hyderabad: Researchers, including a scientist from Hyderabad’s Tata Institute of Fundamental Research (TIFR), have developed and studied two fluorescent sensors that can track acidity levels inside cancer cells, offering a new way to understand changes in cellular compartments linked to disease.By producing different colour signals, the sensors can simultaneously identify where they are inside a cell and measure the acidity of their surroundings.The findings, published in ‘Scientific Reports’ on Oct 13, compare two dual-colour sensors, one based on red-blue fluorescence and the other on red-green fluorescence. The researchers tested the sensors in laboratory solutions and HeLa cancer cells and compared their performance with commonly used cellular markers, MitoTracker and LysoTracker.Tracking acidityThe sensors were designed to target mitochondria and lysosomes, two cellular compartments that operate under very different pH conditions. While lysosomes are highly acidic, mitochondria function in relatively neutral to basic environments.Monitoring these pH differences can help scientists better understand how cells function and how changes in acidity are associated with diseases, including cancer.Both sensors use a piperazine unit to target specific cellular compartments. The red-blue sensor combines pyrene with a rhodamine dye, while the red-green version links naphthalimide to rhodamine.Under acidic conditions, the rhodamine component produces a red fluorescent signal. In mitochondria, the sensors emit either blue or green fluorescence, whereas in acidic lysosomes they generate combined blue-red or green-red signals. This enables researchers to visualise compartment-specific acidity within the same cell.The blue and green fluorescent components also allow the sensors to detect pH changes beyond pH 6, extending their sensing range.Improving cellular imagingThe sensors work through a combination of electron transfer, charge transfer and energy transfer mechanisms between their fluorescent components. Researchers evaluated their behaviour across a range of neutral-to-acidic environments and calculated four different pKa values for the red-green sensor, providing a detailed measure of its acid-base responsiveness.The study notes that analysing ratios between fluorescence signals helps minimise errors caused by differences in illumination or sensor concentration, making measurements more reliable.The researchers describe the molecules as valuable tools for studying pH-related changes tied to cellular function and disease. The experiments reported in the study were conducted in laboratory solutions and cultured cells.The authors include Akshita, Garima Tiwari, Rythem Goyal, Saleem Javed, Shruti Mishra, Swati Singh, Payel Roy, Rajesh Kumar, Priyanka Srivastava, Vikram Singh and Ute Resch-Genger. Among them, Rythem Goyal is affiliated with the TIFR, Hyderabad.You Can Also Check: Gold Rate in Hyderabad | Silver Rate in Hyderabad | Bank Holidays in Hyderabad | Public Holidays in Hyderabad | Hyderabad AQI | Weather in Hyderabad | Petrol Price in Hyderabad | Diesel Price in Hyderabad | CNG Price in Hyderabad | LPG Price in HyderabadStay updated with the latest Hyderabad news. Download the TOI App.