Protein Precipitation by Acetone for the Analysis of Polyethylene Glycol in Intestinal Perfusion Fluid
1979; Elsevier BV; Volume: 76; Issue: 4 Linguagem: Inglês
10.1016/s0016-5085(79)80184-5
ISSN1528-0012
AutoresThomas B. Buxton, Jennifer K. Crockett, William L. Moore, William L. Moore, J. P. Rissing,
Tópico(s)Liver Disease Diagnosis and Treatment
ResumoCanine ileal segments were luminally perfused with known amounts of polyethylene glycol (PEG), and samples obtained were freed of protein by a cold acetone (CA) method and assayed for PEG by trichloroacetic acid in the presence of calcium cations.This procedure was compared to the Barium salt (BaS) protein precipitation method of Hyden (Ann R Agric Coll Sweden 22:411-424, 1955).The CA method saved specimen volume and time in handling, whereas its stability, linearity, and reproduc- ibility were equivalent to the more complex BaS method.In vitro studies disclosed no appreciable differences when PEG specimens were bile stained or dissolved in various solvents.A small modification of the CA method improved accuracy in measurement of small PEG concentrations.Polyethylene glycol (PEG) is used as a non absorbable marker to study water movements in human and animal transport studies.' Schaffer and Critchfield first suggested the use of PEG as a marker in 1947, but offered an analytic method which was difficult and time consuming!Hyden shortened the procedure by using trichloroacetic acid (TCA) and barium cations to form an emulsion. 3This emulsion, however, was unstable and required rapid handling of samples to assure reproducibility of results.Malawer and Powell added gum arabic to
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