How micro is microdissection? Laser removal of stratum corneum of skin to expose the epidermal battery

Steven L. Jacques, Felix E. Ejeckam, Frank K. Tittel

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations

Abstract

How micro is laser microdissection? This study compared the spatial resolution of laser microdissection achieved by two laser systems: the ArF excimer laser which is strongly absorbed by tissue protein, and the Er:YAG laser which is strongly absorbed by tissue water. Both lasers penetrate tissue only a couple microns and are suitable for laser microdissection, and in this report the lasers ablated the outer dead-cell layer of the skin called the stratum corneum. The study involved dorsal skin sites on 8 rats for the ArF excimer and 10 rats for the Er:YAG. Ag/AgCl-gel electrodes were used to measure the passive DC resistance (R) and the active DC voltage (V) of skin sites which had received increasing numbers of ablative laser pulses (9 mJ/pulse, Er:YAG; 48 mJ/pulse, ArF excimer). About 8 pulses were required before a sudden drop in Ra and a sudden rise in V was observed. The R dropped from 4 ± 0.2 (18) Mohm down to 1.5 ± 0.2 (18) Mohm; mean ± standard deviation (number of skin sites). The V was initially -56 ± 5 mV, then dropped to -3 ± 0.4 mV after laser ablation penetrated and destroyed the battery. The Er:YAG laser required 8.3 ± 1.5 pulses to achieve 50% of the full change in R and V; the ArF excimer laser required 76 ± 2 pulses. The changes in R and V per depth of tissue ablated were identical for the two lasers, despite their distinct differences in absorbing chromophore and efficiency of ablation.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Society of Photo-Optical Instrumentation Engineers
Pages23-33
Number of pages11
ISBN (Print)0819411094, 9780819411099
DOIs
StatePublished - 1993
Externally publishedYes
EventLaser-Tissue Interaction IV - Los Angeles, CA, USA
Duration: Jan 18 1993Jan 20 1993

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume1882
ISSN (Print)0277-786X

Other

OtherLaser-Tissue Interaction IV
CityLos Angeles, CA, USA
Period1/18/931/20/93

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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    Jacques, S. L., Ejeckam, F. E., & Tittel, F. K. (1993). How micro is microdissection? Laser removal of stratum corneum of skin to expose the epidermal battery. In Proceedings of SPIE - The International Society for Optical Engineering (pp. 23-33). (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 1882). Publ by Society of Photo-Optical Instrumentation Engineers. https://doi.org/10.1117/12.147667