– 5-(and-6)-FAM (full name: 5-(and-6)-Carboxyfluorescein mixed isomer) has a pKa of 6.5 and can be used as a pH indicator. Its excitation spectrum and fluorescence response to pH are similar to those of BCECF. Carboxyfluorescein can also be used as a tracer dye. The dye is membrane-impermeant and can be loaded into cells by microinjection or scrape loading. 

 
• &lamba;_Ex/&lamba;_Em (pH 9) = 492/514 nm
 
• ε (pH 9) = 82,000
 
• Yellow orange solid soluble in pH>6 water
 
• Store at 4°C and protect from light, especially in solution
 
• C₂₁H₁₂O₇
 
• MW: 376
 
• [72088-94-9]
 

Handling

Store with desiccant; Protect from light