Abstract: Certain transcription factors (enhancer binding proteins) significantly increase transcription rates from genes by nicking a single DNA strand in the vicinity of their DNA binding sites, thereby allowing RNA polymerase to gain access to the transcribed DNA strand by a process of “threading”. DNA template nicking is a detectable and quantifiable byproduct indicative of transcriptional activation that can be used to design practical assays. These assays are used to determine which transcription factors (enhancer binding proteins) are actively catalyzing the transcription of a gene in any cell type, or in any cell in response to any drug or treatment. This group of transcription factors have a predictable molecular biological activity in addition to transcription activation, namely site-specific DNA strand cleavage.

Abstract: The present invention relates to a layered cell sorted tissue that is formed in vitro. The tissue is generated by the spontaneous sorting of cells from a homogenous cell mixture into discrete layers by cell type. Connective tissue components, such as fibronectin, may be used to manipulate orientation of the layers during the cell sorting process. The layered cell sorted tissue may be used as a skin graft for burns, wounds, and ulcers. The tissue may also be used in assays to determine effects of chemicals or drugs on human tissue in vitro as well as provide an in vitro assay for tumor cell metastasis.

Abstract: Methods for the formation of a mammalian skin equivalent are described herein. The method comprises mixing keratinocytes and fibroblasts. The mammalian skin equivalent is also described. The skin equivalent can be made to be normal, abnormal or aging.