The effects of various mammalian sera on attachment efficiency and thymidine incorporation in primary cultures of mouse mammary epithelial cells

Primary retinal and cortical glial cell cultures: effects of medium and serum on attachment and growth

Glial cells of the retina are anatomically distinctive and are thought to contribute importantly to retinal electrophysiology. However, no adequate preparation exists for studying them in isolation, in vitro. This report provides guidelines for primary retinal glial cultures (RET) and compares basal tissue culture features with those for neocortical glia (CX) and the well-studied rat glial line, C6. Cell attachment and growth of RET, CX, and C6 are unique. These differences are explored by the use of specific media and sera. RET attachment, unlike that for CX or C6, was far more sensitive to medium than serum. RET cells attached least quickly, CX most quickly; 4 hr after plating 20% of RET remained unattached. RET growth was poor and relatively insensitive to medium. In contrast, growth of CX or C6 was medium dependent. Serum had substantial effects on the growth of all three glial lines. Pig, goat, horse, and dog sera were particularly effective, often comparing favorably to fetal calf serum. Medium or serum optimal for cell attachment, typically, was not optimal for growth and serum effects were more dramatic than those of medium. By all measures, CX and C6, both derived from brain, were more alike than were the two rabbit primaries, CX and RET. The data reveal substantial differences between presumably similar cells and indicate a need for an empirically based choice of both basal-salt media and serum to optimize specific aspects of cell development in culture.

A quantitative study on growth and cell population identification in murine salivary gland culture

Differentiation of neonatal salivary gland cell populations was studied in vitro using primary explant cultures. Growth on glass of the submandibular, sublingual and parotid salivary glands was optimal if the initial explant diameter was less than 0.4 mm and culture was in 199 medium plus 20 per cent newborn-calf serum. Growth was measured by planimetry of the area of cellular outgrowth as a monolayer with continuous cell contacts. Duct epithelial cells identified using ultrastructural, histochemical and immunological criteria, produced evidence of altered morphology by in-vitro conditions. Preservation of enzymic and antigenic markers of ductal epithelial cell origin in vitro irrespective of gross cell morphology allowed quantification of these cells in a mixed cell population.

Limitations in the use of [3H]thymidine incorporation into DNA as an indicator of epidermal keratinocyte proliferation in vitro

The validity of using the incorporation of [3H]thymidine into DNA as an indicator of epidermal keratinocyte proliferation in vitro has been investigated. Other parameters of cell proliferation, direct count of cell number and measurement of DNA content, consistently fail to correlate with changes in [3H]thymidine incorporation into DNA in primary and first passage cultures of rabbit and human epidermal keratinocytes. Maximum incorporation of [3H]thymidine precedes the active growth period by three days. Incorporation declines markedly during the proliferative period. Thymidine kinase activity decreases during the proliferative growth phase. Incorporation of another pyrimidine nucleotide precursor, [14C]aspartic acid, suggests that in epidermal keratinocytes in vitro the extent of utilization of the salvage and the de novo pathways may be inversely related. In such cases [3H]thymidine incorporation into TCA precipitable material fails to reflect accurately cell proliferation.

Pure melanocyte cultures: differential serum requirements of guinea pig keratinocytes and melanocytes in primary epidermal cell cultures

Contrary to melanocytes guinea pig keratinocytes do not attach and grow in primary epidermal cell cultures if plated in media containing guinea pig serum. This phenomenon is based on the low content or lack of guinea pig serum of a factor(s) promoting keratinocyte attachment. This factor, which is contained in fetal calf serum, binds to the keratinocyte cell surface and can be removed by trypsin. Guinea pig epidermal cell cultures plated in medium containing guinea pig serum therefore lead to pure or almost pure melanocyte cultures.

Effects of serum concentrations on the clonal growth of Syrian golden hamster fetal lung cells

In order to gain an insight into the mechanisms of clonal growth of early-passage Syrian golden hamster fetal lung (SGHFL) cells, a study was undertaken, in which the effects of various serum concentrations on the cloning efficiency and on the colony size of these cells were examined. The results suggest that both cloning efficiency and colony size are influenced by at least two factors present in the serum.

Decreased serum responsiveness by primary monolayer cultures of preneoplastic and neoplastic mammary epithelial cells

Monolayer cultures of normal, preneoplastic and neoplastic murine mammary epithelial cells were exposed to various types of mammalian serum. A progressive decline in levels of thymidine incorporation together with a change in the ordering of sera which stimulates optimal incorporation was observed in the transformed cells.