Detection of Radionuclides in Capillary Electrophoresis Using a Phosphor-Imaging Detector

Abstract

A capillary electrophoresis (CE) postcolumn radionuclide detector has been developed that uses a commercial phosphor-imaging detector and has been optimized for low-energy beta emitters. Eluant from the separation capillary is deposited on a membrane. Emission from radioactive analytes on the membrane is integrated using the phosphor-imaging system for 10-72 h. Results from the phosphor-imaging system are converted to conventional electropherograms. Modifications to a prior postcolumn CE deposition system have been accomplished by adding a buffer makeup capillary; this increases the electrolyte pH range and improves reproducibility. The limit of detection (LOD) for 35S-labeled analytes is 0.13 amol (8.7 pM or 0.007 Bq), while the LOD for 32P-labeled analytes is 4.9 zmol (0.33 pM or 0.002 Bq), with a linear range for 35S-Met from 1.5 amol to 1.5 fmol.

d‐Aspartate as a putative cell–cell signaling molecule in the Aplysia californica central nervous system

“…CE with radionuclide detection is capable of performing pulse‐chase experiments and so can be used to study the synthesis of d ‐Asp from specific radionuclide precursors. We have developed several detection schemes employing CE to detect a range of radionuclides (Tracht et al . 1994, 1996; Page et al .…”

Direct cellular assays using off-line capillary electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

“…A large number of completely independent measurements are possible from CE fractions deposited on planar substrates, including spectroscopic and radiometric assays. 50,51 One disadvantage of MALDI-MS involves the difficulties in quantification, especially in complex matrices. Radionuclide detection offers selectivity (by labeling the newly synthesized peptides using radiolabeled precursors), high sensitivity and quantitative results.…”

Electrofilament deposition and off-column detection of analytes separated by capillary electrophoresis

“…Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) [2], Fourier transform infrared spectroscopy [3], and surface-enhanced Raman spectroscopy (SERS) [4] can provide specific structural information. Additionally, such techniques as post-column radionuclide detection [5], chemiluminescence [6], and fluorescence line-narrowing [7] have been used to detect analytes on planar substrates.…”