The flow behavior of mixtures of micron-sized cubic particles suspended in a concentrated colloidal dispersion is investigated across a broad range of cubic particle concentrations. In the semi-dilute regime, the qualitative shape of the dynamic moduli and flow curves reflect those of the underlying colloidal dispersion medium. These curves are superimposed with the underlying colloidal dispers...

Isolated spinach chloroplasts purified by isopycnic centrifugation in density gradients of Percoll were found to be highly intact, to be devoid of extrachloroplastic contaminations, and to retain a high rate of CO(2)-dependent O(2) evolution.When suspended in a medium which avoided rupture of the envelope, intact purified chloroplasts progressively lost their phosphate content by passive diffus...

Dielectrophoresis is a method of rapid response with sufficient selectivity for manipulation and separation of bioparticles, such as: microorganisms and biomolecules. Due to the great importance of proteins in the biotechnological and pharmaceutical processes, the present study demonstrates the potential of the insulator-based dielectrophoresis (iDEP) and DC electric fields to manipulate and co...

A number of parameters associated with the isolation of plant mitochondria were carefully examined in the hope of optimizing the isolation technique. Dark-grown mung bean (Phaseolus aureus var. Jumbo) hypocotyls were used as the source of mitochondria. Necessary conditions for the isolation of tightly coupled plant mitochondria include: (a) gentle tissue disruption; (b) rigorous exclusion of co...

Acidification of the suspending medium of corn mitochondria (Zea mays L., WF9 x Mo17) from pH 7.5 to pH 6.8 to 6.4 initiates osmotic swelling with the transportable anions citrate, sulfate, and phosphate. Swelling becomes pronounced with a combination of citrate plus sulfate or phosphate. Acidification proves to activate endogenous respiration, which is essentially zero at pH 7.5. The endogenou...

Vacuoles isolated by a mechanical slicing method from developing tubers of Jerusalem artichoke (Helianthus tuberosus L.) contain activities of the two principal enzymes responsible for fructan synthesis: sucrose-sucrose fructosyl transferase and fructan-fructan fructosyl transferase. Both enzymes are associated with the vacuolar sap and not with the tonoplast. In vacuoles isolated from dormant ...

An antigen immunochemically indistinguishable from plasma a2-antiplasmin. the primary plasmin inhibitor. was detected in human platelets. By radioimmunoassay. 331 14 ng a2-antiplasmin antigen was quantitated in the detergent-soluble extract of 1 O washed human platelets from 1 0 normal donors with a mean level of 62 ± 24 ng/1O’ platelets. Plasma a2-antiplasmin. either in the platelet suspending...