Influence of column length and pore size on high-performance ion-exchange chromatography of XXXX and @entity1871 receptors.

@entity172 @entity1 @entity0 @entity1871 @entity1391 @entity17281 @entity3440
A high-performance liquid chromatographic (HPLC) procedure has been evaluated to establish a routine test in the clinical laboratory for measuring the profiles of @entity172 and @entity1871 receptor isoforms in @entity1 @entity0 . This procedure will be used to determine if there is a relationship between particular isoform profiles and response to various endocrine therapies. Evaluation of various HPLC modes has shown that high-performance ion-exchange chromatography (HPIEC) with @entity3440 -based anion exchangers offers a promising approach. In this paper, we have compared HPIEC columns of different lengths (10 and 25 cm) and pore sizes (300, 500 and 1,000 A) in order to obtain an optimal separation procedure. Because of receptor lability, all investigations were performed at 4 degrees C. The mobile phase consisted of 10-500 mM @entity1391 buffer, supplemented with the stabilizing agent, @entity17281 at pH 7.4. Recoveries from each of the columns were between 70-100%. The length of the column did not influence significantly the retention time and salt concentration required for elution of receptor proteins. However, pore sizes appeared to alter these parameters. With a larger pore size (1,000 A), the retention of proteins was lower (elution with 50 mM @entity1391 ) than that observed with the 500-A pore size column (elution with 100 mM @entity1391 ) or of the 300-A pore size column (elution with 150 mM @entity1391 ). Based solely on recovery patterns and peak shape, we conclude that separation of receptor isoforms on a 1,000-A, 25-cm column is best suited for clinical analysis.
