Types Of Culture Vessels Research Articles

The Regulation of Somatic Embryo Development in Plant Cell Cultures: Suspension Culture Techniques and Hormone Requirements

The ability to control plant somatic embryogenesis is a necessary prelude to its development as an efficient biotechnological tool. The influence of different suspension culture techniques on the maturation of caraway (Carum carvi) somatic embryos and the effect of growth hormones in controlling development were studied. The three types of culture vessels (tumble tubes, test tubes, and Erlenmeyer flasks), each providing contrasting techniques of agitation, generated populations differing significantly in the frequencies of normal and abnormal embryos. Abscisic acid (ABA), at the appropriate concentrations, effectively normalized development in all systems, inhibiting abnormal proliferations and precocious germination and fostering normal maturation. For those cultures where embryos failed to develop on unsupplemented medium, zeatin in combination with ABA fostered growth and normal maturation. Carrot (Daucus carota) somatic embryo development could be similarly controlled. Such regulation of maturation would facilitate future efforts to manipulate somatic embryos for large scale propagation in batch cultures, mechanized planting, artificial induction of dormancy, and incorporation into artificial seeds.

Schistosoma mansoni: Long-term culture of in vitro derived schistosomula

In vitro derived schistosomula were cultured under various conditions. Variables tested included concentration of organisms, type of culture vessel, frequency of media change, time of erythrocyte addition, antibiotic levels, heated vs unheated serum in the media, and fresh vs stored serum or erythrocytes. No differences were observed between cultures changed every 3 or every 7 days, but worm growth and development were retarded when the culture medium was changed every 2 weeks. Organisms cultured without changing the medium for 3 weeks did not survive. High levels of antibiotics also inhibited growth and resulted in increased mortality. None of the other factors tested resulted in remarkable differences between groups. Some cultures lived for as long as 69 days, and pairing of adult worms was observed as early as 55 days. Most of the cultures, however, were lost before that time from the outgrowth of contaminants which were probably present in the cultures from the outset.

Temperature responses of a coccolithophorid, Cricosphaera carterae, measured in a simple and inexpensive thermal‐gradient device1

An illuminated thermal‐gradient device is described which is of simple construction, very low cost, and wide adaptability to various culture vessels. It can be readily adapted for use in crossed gradients with temperature along one axis. The thermal gradient produced depends on several factors including the heat source (one or more incandescent lamps), heat sink (cold air in a refrigerated box or room), and type of culture vessel. By use of the device, the temperature range for growth of Cricosphaera carterae was found to be 10–26°C, with a maximal growth rate at 20°C.

An improved culture flask for photographic and visual observation of living cell cultures

A new type of culture vessel is described, identical in shape to the classic T15 vessel but with the advantage of optical surfaces that allow photography at medium resolution (with numerical apertures of 0-60-1-0). Details of flask manufacture are given.

Large scale culturing of normal diploid cells on glass beads using a novel type of culture vessel

Normal diploid fibroblasts are grown in a special culture chamber filled with glass beads which provide a large surface necessary for mass cell culturing. The vessel is supplied automatically with fresh nutrient medium by controlling the pH of the outflowing medium which is either re-circulated or disposed of. The apparatus allows a tenfold increase of a given number of cells within 1 week without any manual work during this time.

Plaque titration of herpes simplex with antibody-free liquid overlay.

SummaryTwo reliable methods for plaque titration of herpes simplex in antibody-free liquid culture medium have been described. Some advantages over plaque titrations with solid or antibody-containing overlays are elimination of inhibitory effects of agar and antiserum, greater choice in type of culture vessel which allows for saving of culture materials, technician's time, and incubator space, optional elimination of carbon dioxide incubators, greater range of magnification, and more flexibility in manipulation of cultures.

A Note on the Respiration of Bacillus coli.

The respiration of prepared aliquots of a suspension of Bacillus coli has been used extensively in this laboratory for comparing the calibration-constants of different Bareroft-Haldane differential manometers and their culture-vessels. The great accuracy of the observations has brought to light an hitherto unreported phenomenon in the oxygen-absorption of this organism. The suspension of bacteria grown on agar for 18 hours was washed off with 10 cc. of broth, filtered through sterile cotton, and 0.1 cm. of the resulting suspension was placed in the vessel of the respirometer after further diluting it with 10 cc. of broth. The oxygen-uptake was observed at this final dilution at 37°C. Plating showed the cultures to be pure at the end of the experiment. It was found that the rate of oxygen-uptake increased logarithmically, as would be expected, until the culture reached the age of about 3 hours and 40 minutes. At this time a new rate was initiated. The course and magnitude of this change is seen in Table I and plotted on Fig. 1. Many similar experiments were carried out, all of which showed the break in the curve at very nearly the same age (Table III). The results tabulated in Table I11 were obtained with different manometers and in various types of culture-vessels. These experiments were carried out at irregular intervals over a period of several months during which time many different batches of broth were used In order to make sure that the break in the curve would be as sudden as manometric readings at 10-minute intervals indicated, the readings were made at intervals of 2 minutes. From data presented in Table I1 and plotted on Fig. 2, it may be seen that the transition in rates surprisingly occurred within a 2-minute interval.