SELECTIVE FLUOROGENIC DERIVATIZATION OF A PEPTIDE NUCLEIC-ACID TRIMERWITH NAPHTHALENE-2,3-DICARBOXALDEHYDE

The reversed-phase high-performance liquid chromatography of a Peptide Nucleic Acid (PNA) trimer has been studied after its preseparation fl uorogenic derivatization with naphthalene-2,3-dicarboxaldehyde in the presence of cyanide (NDA/CN). Trace levels of the PNA trimer were dete rmined in cell homogenate samples containing the PNA trimer at prederi vatization concentrations as low as 48.9 ng ml(-1). The sample pretrea tment operations included a deproteination step, achieved by ultra-fil tration, followed by fluorogenic derivatization (NDA/CN). Subsequently , to achieve adequate selectivity, the fluorescently labeled PNA was s ubjected to high performance anion exchange chromatography prior to qu antitation via fluorescence detection. The various problems encountere d during sample pretreatment and separation of derivatized PNA trimer in biological samples are presented and discussed. (C) 1997 Elsevier S cience B.V.