From experiments with purified proteins, it has been concluded that factor XIa (FXIa) is inhibited in plasma mainly by alpha 1-antitrypsin (a1AT), followed by antithrombin III (ATIII), C1-inhibitor (C1Inh), and alpha 2-antiplasmin (a2AP). However, the validity of this concept has never been studied in plasma. We established the relative contribution of different inhibitors to the inactivation o...

Usable life of cleaning solutions in a model heat processing unit was studied by evaluation of the nature and quantity of residue remaining on the surface of the equipment after cleaning. Lipoidal residue was recovered from equipment surfaces by ether rinsing. A surface displacement technique was used to quantify the lipoidal material, which was characterized by gas-liquid chromatographic analy...

We have developed a reliable radioimmunoassay for testosterone in plasma, polyethylene glycol ("Carbowax 6000") being used to separate antibody-bound and free hormone. Testosteron is separated from interfering steroids, notably dihydrotestosterone, by liquid-liquid partition chromatography on infusorial earth (Celite). The assay is sensitive (9 pg for standards), precise, and accurate. The lowe...

A large scale isolation of a disaccharide from a dialyzable fraction cf Micrococcus Zysodeikticus cell wall is described. This fraction was obtained by degradation of isolated walls with egg white lysozyme. After purification by chromatography on charcoal-Celite 2nd Dowex 1, the compound was characterized by a crystalline heptaacetyl methyl ester. Comparison with synthetic 0-2-acetamido-2-deoxy...

A bstract. This paper describes a new method for qualitative and quantitative assay of abscisic acid and other acidic plant hormones, such as indoleacetic acid and the gibberellins, by the gas-liquid chromatography of their trimethylsilyl derivatives. Interfering substances in plant extracts were largely removed by preliminary oolumn chromatography with carbon-celite and elution of the absoisic...

We developed and validated a coordinated set of RIAs for the following eight steroids in single small aliquots (< or = 1 mL) of plasma: androstenedione, dehydroepiandrosterone, 11-deoxycortisol, 21-deoxycortisol (21-DF), 11 beta-hydroxyandrostenedione, 17 alpha-hydroxypregnenolone (17-Hpreg), 17 alpha-hydroxyprogesterone, and testosterone. Samples were extracted and then chromatographed on celi...

Heteroand homopolymers prepared from α-amino acid-N-carboxyanhydrides (NCAs) monomers are widely useful products. The preparation of pure NCA monomers has been extensively studied in the past. Purification methods including repeated crystallizations, extraction, and flash column chromatography have been devised. However, these methods are not easily amendable to large-scale NCA preparations. Th...