Method for transdermal nucleic acid sampling

Abstract

A minimally invasive transdermal nucleic acid sampling method comprises piercing through the outermost layer of the skin and into the underlying epidermis with a plurality of microprojections. Living skin cells in the underlying epidermis are disrupted, causing them to release their contents including their nucleic acids (i.e., DNA, RNA, fragments thereof or other polynucleic acid material found in the nucleii and/or mitochondria of cells). The nucleic acid is collected on the surfaces of the microprojections and/or in a separate nucleic acid collection reservoir. The collected nucleic acid is then analyzed using standard polymerase chain reaction (PCR) techniques. Optionally a suction device applies a partial vacuum through openings in the microprojection member to the microcuts in the skin for enhanced efflux of intracellular and extracellular (i.e., body) fluids containing the nucleic acid.

1 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         2 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting nucleic acid from the disrupted or dislodged skin cells by allowing the microprojection to become at least partially coated with nucleic acid-containing body fluid and withdrawing the microprojection from the skin; and analyzing the nucleic acid.  
     
     
         3 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting nucleic acid from the disrupted or dislodged skin cells by absorbing a nucleic acid-containing body fluid into an absorbant material on the microprojection; and analyzing the nucleic acid in the absorbant material.  
     
     
         4 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells by applying negative pressure to the pierced skin; and analyzing the nucleic acid.  
     
     
         5 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer to a depth of less than about 500 μm with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         6 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a plurality of skin-piercing microprojections and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         7 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a multiplicity of skin-piercing microprojections and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         8 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin to a depth of at least about 25 μm and into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         9 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with an array of skin-piercing microprojections, the array having a microprojection density of at least about 10 microprojections/cm 2 , and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         10 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting nucleic acid from the disrupted or dislodged skin cells on a surface of the microprojection; and analyzing the nucleic acid.  
     
     
         11 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a skin-piercing microprojection and disrupting or dislodging skin cells containing nucleic acid; collecting the nucleic acid from the disrupted or dislodged skin cells in an absorbant matrix, which matrix is in nucleic acid-collecting relation to the microprojection; and analyzing the nucleic acid in the absorbant matrix.  
     
     
         12 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a plurality of skin-piercing microprojections extending from a sheet having a plurality of openings therethrough, said piercing causing disruption or dislodging of skin cells containing nucleic acid; collecting nucleic acid from the disrupted or dislodged skin cells; and analyzing the nucleic acid.  
     
     
         13 . A method of transdermally sampling nucleic acid comprising:  
       piercing through the stratum corneum layer of skin into at least an underlying epidermis layer with a plurality of skin-piercing metallic microprojections extending from a metallic sheet having a plurality of openings therethrough, said piercing causing disruption or dislodging of skin cells containing nucleic acid; collecting nucleic acid from the disrupted or dislodged skin cells by withdrawing a body fluid containing the nucleic acid through said openings; and analyzing the nucleic acid.  
     
     
         14 . The method of any of  claims 1  to  13 , wherein the nucleic acid is analyzed by polymerase chain reacion assay.  
     
     
         15 . The method of any of  claims 1  to  14 , wherein he skin is the skin of a human.  
     
     
         16 . The method of any of  claims 1  to  15 , wherein the nucleic acid is selected from the group consisting of DNA, DNA fragments, RNA, RNA fragments, genes, chromosomes, and polynucleic acid sequences.