Unexpected Fluorescent signal

[Username1234]

Sometimes, a green fluorescent signal will be visualized when examining a sample with a red filter. Why?

and how would you fix this?

I don't understand this question... how would that even be possible? Anyone?

[canalon]

autofluorescence.

[Username1234]

Thanks for your answer
Could you please be more descriptive? Where is the auto fluorescence coming from? The material that the cells are cultured on? The cells themselves?

How would you fix that?

[bluetutu]

There are two fluorescent phenomena, one is called auto-fluorescent (Phosphorescent), the other is called fluorescent. Auto-fluorescence is a very slow process, it can stay a very long time. Fluorescence is caused by energy emission from fluorophore which is a protein complex like a core surrounded by peptide (Fluorescent Proteins, e.g. Green Fluorescent Protien, Yellow Fluorescent Protein...). Fluorescense is stronger than autofluorescense, but the signal will quickly die after excitation...call Bleaching.

[Username1234]

thanks but that doesn't answer my question at all. Please read the question.