How to convert the Florosence value to activity in-beta hexosaminidase assay.

Usually we do not use a stand curve of beta -hexosaminidase enzyme to calculate the activity. Instead we normaize beta-hexosaminidase values to total protein amount in cell supernatant and extracts. 

So for each sample β-hexosaminidase (β-hex) activity is calculated by normalizing to total protein amount as following: 

β-hex activity in supernatant = [fluorescence (365/450) - HBSS alone]/protein µg. 

β-hex activity in cell lysate = [fluorescence (365/450) – lysis buffer alone]/protein µg. 

Total β-hex activity = β-hex activity in supernatant + β-hex activity in cell lysate. 

Finally, the percentage of β-hex secretion is calculated as follows: β-hex secretion (% of total) = 100 x (β-hex activity in the supernatant/total β-hex activity.