DETECTION OF POLYCYCLIC AROMATIC COMPOUNDS IN SINGLE LIVING CELLS USING OPTICAL NANOPROBES

Abstract

Exposure of mammalian cells to polycyclic aromatic compounds (PACs) such as the carcinogen benzo[a]pyrene (BaP) leads to the formation of DNA adducts N2-deoxyguanosine (dG) and N6-deoxyadenosine (dA) with adenine and guanine nucleotides, which are integral parts of DNA, RNA, and ATP. DNA adduct formation causes alteration of the DNA (RNA) sequence since neither adenine nor guanine can normally bind to its complementary nucleotide base, thymine (uracil) and cytosine respectively. The inability to form these bonds leads to mutations in the DNA double-helix structure during DNA replication, and eventually carcinogenesis. Therefore, the capability to detect and measure PAC species such as BaP in single living cells is important for studies required to establish the limits of BaP exposure necessary for carcinogenesis. Along these lines, we have developed antibody-based optical nanoprobes capable of detecting and measuring BaP in single living cells. The results obtained in this work demonstrate the practical application of antibody-based nanoprobes for performing measurements inside single living cells with their elements and their relationships intact.