Alternative surfaces for microcarrier culture of animal cells.

As part of an effort to broaden the applicability and efficiency of microcarrier cell culture various alternative new microcarriers were synthesized. The microcarriers were compared as substrates for the growth of several types of cells and with respect to binding of proteins from the culture medium. Cross-linked dextran has been found to be the most suitable material for a microcarrier matrix and was used as the matrix for the new microcarriers.

Alternative surfaces for microcarrier culture of animal cells.

As part of an effort to broaden the applicability and efficiency of microcarrier cell culture various alternative new microcarriers were synthesized. The microcarriers were compared as substrates for the growth of several types of cells and with respect to binding of proteins from the culture medium. Cross-linked dextran has been found to be the most suitable material for a microcarrier matrix and was used as the matrix for the new microcarriers.

Serum supplements and serum-free media: applicability for microcarrier culture of animal cells.

Several different combinations of serum supplements and also serum-free media were examined for their ability to support the growth of MRC-5 and Vero cells on Cytodex microcarriers. Greater economy of serum was achieved for routine microcarrier culture by selecting the type of serum supplement, on the basis of whether the supplement was to support attachment and growth of cells at low densities or growth of cells at later stages in the culture cycle. Further economy was achieved by altering the serum concentration according to the requirements of each stage of the culture cycle.

A comparison of various laboratory scale culture configurations for microcarrier culture of animal cells.

When developing procedures for microcarrier culture it is important to use equipment which results in even suspension of microcarriers with minimal shear forces and which permits maximum growth of the culture. A variety of different laboratory scale culture systems were investigated including traditional magnetic spinner flasks, modified spinner flasks, cultures stirred with bulb-shaped rods and a fluid lift culture system. All systems were compared with respect to growth of either MRC-5 or Vero cells on Cytodex microcarriers.

Optimizing culture conditions for the production of animal cells in microcarrier culture.

Cytodex 1 microcarriers have been used for the successful culture of more than 80 different types of animal cells--including primary cells, normal diploid cell strains and established or transformed cell lines. culture volumes have ranged from a few milliliters for diagnostic studies to over several hundred liters for vaccine production. Experience with this wide variety of cell types and culture volumes has enabled the identification of several parameters critical for obtaining maximum cell yields from microcarrier cultures.

High yield culture of human fibroblasts on microcarriers: a first step in production of fibroblast-derived interferon (human beta interferon).

Production of large quantities of diploid human fibroblasts in small culture volumes can be achieved using microcarrier culture techniques. Modification of the microcarrier culture procedure to include a virtually static attachment period and a reduced culture volume during the first 6 hr of culture was shown to double the attachment efficiency of the cells, improve the culture growth rate and increase final cell yields. Using the modified culture procedure yields greater than 2 x 10(6) cells/ml could be regularly obtained when 7--8 viable cells/microcarrier were used to inoculate a culture containing 3 mg of Cytodex 1 microcarriers/ml.

Microcarriers for animal cell culture: a brief review of theory and practice.

Microcarrier beads for animal cell culture are considered in relation to aspects of cell adhesion and growth. Some "critical parameters" for a successful microcarrier are discussed, comparing currently available materials. The properties most critical for a successful microcarrier were closely fulfilled by the microcarrier CytodexTM 1 which has been used for the successful cultivation of more than 60 different cell types.

A convenient synthesis of labelled rhodopsin and studies on its active site.

Digitonin solutions of labelled rhodopsin, containing (3)H in the retinyl moiety, were prepared by two related methods. Labelled rhodopsin was also prepared for the first time in cetyltrimethylammonium bromide and purified by column chromatography. It was shown that only certain rhodopsin preparations on denaturation in the dark and the reduction with sodium borohydride gave up to 60% of the radioactivity in a fraction characterized as N-retinylphosphatidylethanolamine.