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Working at pressures of up to 2000 atmospheres, more than ten times higher than in previous gas chromatography, we used the solvent power of dense gases to enable migration of chromatographic substances of molecular weights as high as 400,000. Carotenoids, corticol steroids, sterols, nucleosides, amino acids, carbohydrates, and several polymers have been caused to migrate, separated, and detected in NH(3) and CO(2) carrier gases at temperatures of 140 degrees and 40 degrees C, just above the respective critical points. Previously such compounds either defied separation by gas chromatography or had to be chromatographed as their more volatile derivatives.

Turbulent flow in gas chromatography was achieved and its effect was studied with high-speed, high-pressure equipment. A gas-solid capillary and several packed columns were used. The onset of turbulence was associated with abrupt decrease in peak width in the capillary and gradual leveling off and decrease in the Packed width in the existence of separation under turbulent conditions was shown. The Potential of the method was demonstrated by its short elution times and generation of theoretical Plates.

Cryoprecipitate antihaemophilic factor concentrate was prepared from fresh and 24-hour-old blood by quick and slow thaw methods. Recovery of factor VIII was greater by the slow thaw method and there was less loss into the supernatant plasma. Cryoprecipitate produced from fresh blood contained more factor VIII than that produced from 24-hour-old blood so that the most potent concentrate was produced from fresh blood by the slow thaw process. An adequate therapeutic preparation was, however, produced by the slow thaw method using 24-hour-old blood and it is suggested that this procedure could be adopted in order to supplement supplies.

Fibrinogen concentrations were determined in normal plasma and in plasma from patients with high and low levels. There was a good correlation between the results of a rapid semi-quantitative fibrinogen titre technique and those of a quantitative assay of coagulable fibrinogen. In normal subjects fibrinogen levels were not significantly influenced by taking blood into epsilon aminocaproic acid (EACA) or by the addition of protamine to plasma. In patients with the defibrination syndrome in whom increased plasma fibrinolysis was not detected, fibrinogen levels were not affected by taking blood into EACA but considerably increased levels were observed after the addition of protamine to plasma. In patients undergoing thrombolytic therapy the fibrinogen levels measured were increased both in blood taken into EACA and in plasma containing protamine. It is suggested that EACA acted by preventing lysis in vitro whilst protamine counteracted abnormal fibrin polymerization. The pattern of results may be of diagnostic importance.

Protein separation has been achieved by electrical field-flow fractionation, a heretofore unrealized separation technique. Some advantages of this method relative to electrophoresis are the low voltage required, the lack of adverse heating and support effects, and the existence of the method as an elution technique. A comparison of theoretical and experimental retention shows good agreement.