| Abstract
| - A novel approach is described that uses capillary electrophoresis (CE) to electrophoretically sample and separate both protein and RNA from a single injected plug ofcell lysate. A 250-pL sample of lysate from Chinesehamster ovary cells (9.6 × 107 cells/mL) was hydrodynamically injected into a capillary containing a Tris-based aqueous buffer. This was followed by selectiveelectrokinetic ejection of RNA from the lysate into water,yielding an effective cell concentration of RNA of 3000cells/mL. The cellular components (e.g., proteins) retained in the capillary were separated and then detectedwith laser-induced fluorescence (LIF) using 275-nmexcitation. The ejected/diluted sample was subsequentlyinjected into a separate CE-LIF system, which utilized anentangled polymer sieving matrix and 543-nm excitationfor the detection of ethidium bromide-labeled nucleicacids (i.e., RNA). Virtually no sample preparation isrequired other than simple washing and lysing of the cellsisolated from culture. This combined approach can beeasily modified for the detection of any analyte throughadjustment of CE-LIF conditions. In addition, it providesan effective method for desalting cellular RNA sampleshaving complex matrixes, which results in improved RNAinjection efficiency and a 7600-fold effective signal enhancement over total lysate injection.
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