Chip Electrophoresis as a Method for Quantifying Total Albumin in Cerebrospinal Fluid

Abstract

T he cerebrospinal/serum albumin ratio (Q Alb ) is a measure of cerebrospinaleblood barrier permeability, where dysfunctional barriers have been associated with a variety of disease states. Thus, the ability to accurately quantify albumin has critical diagnostic importance. The current work uses chip electrophoresis as an alternative methodology to the conventional immunoassay for quantifying cerebrospinal fluid (CSF) albumin. With variable concentrations of bovine serum albumin normalized to a chicken albumin internal standard, the electrophoresis system demonstrated signal correlation with a best-fit polynomial (R 2 ¼ 0.9993) (concentration range of 7.8e1000 mg/L). Interchip and intrachip variation studies conducted on patient CSF demonstrated coefficient of variations of 0.1e17%. Chip electrophoresis detected an average of 24% greater albumin than the immunoassay in patient CSF samples (n ¼ 58), indicating the ability to detect immunoreactive and non-immunoreactive forms of albumin. Finally, the correlation of CSF albumin concentration to Q Alb determined by chip electrophoresis (r 2 ¼ 0.8683) was comparable with that determined by immunoassay (r 2 ¼ 0.8390). Therefore, this work demonstrates proof-of-principle that chip electrophoresis can serve as an alternative method for quantifying total (immunoreactive and non-immunoreactive) albumin in CSF.

Production and Characterization of a Camelid Single Domain Antibody–Urease Enzyme Conjugate for the Treatment of Cancer

“…Because of the complexity and the size of the conjugate, which can have a molecular weight up to 680 kDa, the conjugation chemistry, reaction, and separation procedures were developed to address the challenges in large-scale production. Because urease has multiple potential conjugation sites for the selected antibody, the conjugation ratio of L-DOS47, which is essential to drug potency, was characterized using an Experion SDS microchannel gel electrophoresis system. , L-DOS47 conjugate purity was determined by size exclusion chromatography. The chemical identity of L-DOS47 was characterized by mass spectrometric peptide mapping and Western blot.…”

“…Because urease has multiple potential conjugation sites for the selected antibody, the conjugation ratio of L-DOS47, which is essential to drug potency, was characterized using an Experion SDS microchannel gel electrophoresis system. 19,20 L-DOS47 conjugate purity was determined by size exclusion chromatography. The chemical identity of L-DOS47 was characterized by mass spectrometric peptide mapping and Western blot.…”