title: UV transmission measurements of small skin specimens with special quartz cuvettes.
abstract: BACKGROUND
  The penetration of different wavelengths of UV radiation through human skin is of major importance, especially for the determination of photoprotective properties of sunscreens and UV-protective clothes.
  
  
  OBJECTIVE
  In this study we present a new method for the measurement of UV transmission through small skin specimens.
  
  
  METHODS
  The transmission measurements were performed by using a UV spectrophotometer with an integrating sphere operating in the wavelength range of 280-390 nm. For the skin samples, special quartz glass cuvettes were developed which allowed measurements for very thin and small skin specimens. Furthermore, the cuvettes prevented dehydration of the specimens and guaranteed, by using an additional diaphragm, that the transmission data were derived solely from the small skin specimen examined. Specimens measuring 8 x 3 mm(2) with a thickness of 0.3 mm (histometric and sonographic control) were taken from the thighs of 10 subjects via shave biopsy.
  
  
  RESULTS
  In the UVA range (315-390 nm) we obtained a mean transmission of 4.6% and for the UVB range (280-315 nm) of 0.9%. No significant (p >0.14) difference of UV transmission was found between the individual skin specimens.
  
  
  CONCLUSIONS
  This new method seems to be well suitable for UV transmission measurements of small skin specimens. As UVA radiation has a much deeper penetration depth and in in vivo situations dermal hemoglobin could have an effect on UV penetration, the present method is better suitable for the investigation of UVB-induced biological adaptation mechanisms and the impact of topical agents on UVB transmission of the epidermis.
authors.affiliation: Department of Dermatology, Ruhr University, Bochum, Germany. K.Hoffman@derma.de
authors.forename: K
authors.initials: K
authors.lastname: Hoffmann
authors.forename: K
authors.initials: K
authors.lastname: Kaspar
authors.forename: P
authors.initials: P
authors.lastname: Altmeyer
authors.forename: T
authors.initials: T
authors.lastname: Gambichler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D011791:Quartz; D011834:Radiation Monitoring / Q000295:instrumentation* / Q000379:methods; D012867:Skin / Q000528:radiation effects*; D012869:Skin Absorption; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D011791:Quartz