SEPARATION OF HELA CELLS BY COLLOIDAL SILICA DENSITY GRADIENT CENTRIFUGATION

Separation of Hela Cells by Colloidal Silica Density Gradient Centrifugation

Using a colloidal silica density gradient, HeLa cells in mitosis were found to have a density of 1.040-1.046 g/cc, lighter than the remaining interphase cells. The mitotic cells could be harvested and cultured after centrifugation, showing growth synchrony by measurement of a peak in mitotic index 21 hr after establishing the culture. By using Colcemid or vinblastine sulfate, HeLa cells were ar...

Separation of Thyroidal Iodoproteins and Purification of Thyroglobulin by Gel Filtration and Density Gradient Centrifugation.

Thyroglobulin, the major protein component of normal thyroid glands, contains more than 80% of the thyroidal iodine and has been considered the only source of thyroid hormones (1). Aqueous thyroid extracts contain, besides thyroglobulin, other proteins in variable amounts. Essentially, four methods have been used for the characterization of the various components in such extracts and for the pu...

Separation of Adenosine Triphosphatase of HK and LK Sheep Red Cell Membranes by Density Gradient Centrifugation

Membrane fragments from high potassium (HK) and low potassium (LK) sheep red cells were separated by density gradient centrifugation. Three preparations were studied: (1) HK membranes sonicated for 20 minutes, (2) HK membranes sonicated for 3 minutes, and (3) LK membranes sonicated for 3 minutes. The adenosine triphosphatase (ATPase) activity in the maximally disrupted preparation (1) was not s...

Separation of cryptosporidium oocysts from fecal debris by density gradient centrifugation and glass bead columns.

A method was developed to obtain purified cryptosporidium oocysts from fecal samples. Oocysts were initially collected by centrifugation through a sucrose density gradient and further purified by passage through glass bead columns. The purified oocysts were antigenically active and sufficiently pure for immunological studies.

Separation of thrombin-treated platelets from normal platelets by density-gradient centrifugation.