Skin was removed from the back of a slaughtered mini pig
which had been in the control group of one of our former studies
(Burild et al., 2015). Thus had never been exposed to UV light,
but stored at 20 C for 2 years prior to the removal of the skin.
Any hair and subcutaneous fat was carefully removed from the
skin. A normal ruler and a scalpel were used to cut the skin into
pieces of 1 1 cm. The average weight of the samples was
0.498 ± 0.015 g. All samples were kept at 20 C before and after
exposure to UV light. Prior to exposure the samples were thawed
to room temperature. After exposure the samples were kept in airtight
nitrogen-flushed bags. Control-samples, i.e. skin samples
which were not exposed to UV light, were included in the study.
All samples before and after the experiment were kept in an
UV-free environment.
2.2. The UV-LED equipment
Twelve UV-LEDs, emitting wavelengths in the range