Cross-linked Dextran Gel Research Articles

ON THE MOLECULAR WEIGHT OF PREGNANT MARE'S SERUM GONADOTROPHIN.

ABSTRACT The chromatographic behaviour of pregnant mare serum and of a purified preparation of the gonadotrophin from uterine endometrial cup secretion on the cross-linked dextran gel media Sephadex G-100 and G-200 has been examined, and is consistent with a molecular weight greater than the value of 28 000 usually accepted. The sedimentation coefficient of an active preparation has been determined by sedimentation in a sucrose density gradient and serial bioassay. The value of 3.2 S for SW20 is consistent with current values. The literature data are shown to be most consistent with a molecular weight of 68 000 for the hormone, and the mechanism of its chromatography on dextran gels is discussed.

Chromatographic separation of haemoglobin and myoglobin on "Sephadex" gel.

THE separation of bovine carboxyhaemoglobin and whale carboxymyoglobin by ion exchange chromatography on DEAE-cellulose has been described by Brown1. Recently, Flodin2 has discussed the fractionation of some peptides and proteins utilizing the molecular sieve action of cross-linked dextran gels (‘Sephadex’). In the course of our work on the chromatography and microheterogeneity of myoglobin, we have found that oxyhaemoglobin and ferrimyoglobin can be easily separated on ‘Sephadex G-75’ and ‘Sephadex G-50’ columns.

Fractionation of urinary mucosaccharides by gel filtration.

AbstractHexose, hexosamine, sialic acid, fucose, glucuronic acid and tyrosine are studied in fractions obtained by filtration of human and rat urine on a high cross-linked dextran gel column.The nondialyzable material separates rather well from the dialyzable material, as one fraction with tailing. Two subfractions are obtained from the latter, at least for hexose, sialic acid and glucuronic acid. A rather high hexose and sialic acid content, and low hexosamine and tyrosine content characterize the first of these suhfractions. It is suggested that a part of the carbohydrates, including sialic acid and hexosamine, exists in free form in the second dialyzable fraction.Small differences in the distribution of carbohydrates seem to exist between human and rat urine. Surgical stress is followed by an increase of mucosaccharides in all fractions.

Purification and concentration of dye-protein conjugates by gel filtration.

IT was shown by Porath and Flodin1 that filtration through cross-linked dextran gels served as a simple method for the separation of materials of varying molecular size. This procedure has now been found to be of particular value for the purification of antibody-fluorescent dye conjugates for use in the Coon's2 technique, since unconjugated dye and dye impurities are removed so that non-specific staining of the tissues has thereby been greatly reduced or abolished.