Hello everyone,

I have to cross-link a decellularized ECM gel 3D printed samples through UVA irradiation. The area of my sample is equal to 4.7 cm x 6.7 cm.

In literature, I have found out an example in which they use a 370 nm wavelength with a power of 30 mW/cm2 for 3 minutes. This is my goal.

In our lab, I can use a VL-4.LC lamp which emitted 4 W at 365 nm through a 4.7 cm x 7 cm flat screen. The only technical specification on the manufacturer's website is a power of 350 µW/cm2 at 365 nm wavelength at 15 cm distance from the source.

The distance from the source of my sample (in the configuration that we have designed in our lab) is equal to 3 cm. Do I have to modify the irradiation distance or is it enough to change exposure time? Can anyone explain me how to calculate these two variables according to the specific needs, please?

Thank you

All my best