Hi,
I am doing a calcium assay with an indicator dye using cell lysate.I have got a good calibration curve with standard solution provided by the company.However I cannot detect any fluorescence in the cell lysate with the indicator.Even addition of a standard solution of calcium to the lysate is showing no fluorescence.I am using a HEPES based buffer for cell lysis.

Can you name the specific kit you are using and give the precise recipie of your lysis buffer and we might be able to help.