Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Bacteria cell culture contamination

Bioassays appeared to fit the bill to perform this service to monitor chemical contamination. They have been around for a while. Until relatively recently, however, they remained in the realm of the laboratory. Only over the last two decades have they found a niche in testing for toxic chemicals in water and sediment, but not yet specifically as a tool for routine water quality monitoring. As Small-scale Freshwater Toxicity Investigations, Volumes 1 and 2 amply demonstrates, the science has now come of age. Assays based on bacteria, microscopic or multi-cellular algae, protozoa, invertebrates and vertebrates (freshwater fish cell cultures) are discussed in... [Pg.439]

Another factor to be taken into account when using animal serum is the potential risk for human health, due to the possible presence of adventitious agents, such as virus and proteins as prions. In addition, serum can contain contaminants such as bacteria, fungi, and mycoplasmas (small bacteria without cellular walls), which can negatively affect cell culture. [Pg.121]

The production of heterologous proteins for therapeutic use requires selection of the producer cell line, based on yield, monoclonality (for proteins), product quality, stability, and absence of contaminants like bacteria, molds, mycoplasmas, and viruses. Progress in the production of biopharmaceuticals by cell culture is due mainly to the use of diploid cells and continuous cell lines, together with the maintenance of cells by cryo-preservation. It is important to guarantee that the expression system chosen is able to generate the product in a consistent and economically feasible way (Levine and Castillo, 1999). [Pg.355]

In the event of cell cultures becoming contaminated with bacteria, fungi or mycoplasmas, the best course of action is to discard the culture, check cell culture reagents for contamination, thoroughly disinfect all safety cabinets and work surfaces and resuscitate a fresh culture from previously frozen stock. In the case of contamination with a spore-forming organism, and where such facilities exist, room fumigation may also be advisable. [Pg.50]

The need for cell cultures for tests with viruses requires the incorporation of controls over and above those necessary for working with bacteria. In addition to cell culture controls to demonstrate lack of contamination and vims controls to demonstrate a functioning assay system, the level of input vims and the loss in virus infectivity upon the drying of the inoculum on the carrier need to be measured. In some cases, these measurements are only made once and the data used with a series of tests. However, it is recommended that, for proper accuracy, such measurements should be included with every test due to inherent variations in cell cultures and viruses. When there is a need to separate virus kill from simple mechanical removal of the test vims during the test, it is recommended that a control also be included to determine the mechanical removal of the test virus standard hard water should be used for this purpose in place of the test topical product. For any claim of topical antisepsis, reduction in the vims titer on treatment with the test product must be substantially higher than that obtained with the standard hard water treatment alone. [Pg.407]

The major source of failure associated with the culture of mammalian cells (indeed, any type of cell) is the problem of contamination by microorganisms, especially the bacteria that are always present to some degree in virtually every laboratory and manufacturing environment. Animal cell cultures are susceptible to being overwhelmed by bacteria because of the substantial difference in the doubling times typically associated with animal cells (ca. 24 h) and bacteria (ca. 30 min) (47). Over the course of a day the number of animal cells present in a culture will merely double, whereas the number of bacteria will increase by a factor in excess of 10 ". When one fails to maintain aseptic conditions, the explosion in the growth of the cell population is clearly centered in the bacteria. [Pg.503]

A classic example of a clarification process used in Brazil is that of ethanol production by yeast Saccharomyces cerevisiae. The viability of ethanol production is based on the efficiency of the clarifying operation, which depends on the recycling of yeast to the fermentation reactor and, consequently, the maintenance of high cell concentrations in the culture medium. " Another relevant aspect for the appropriate process performance is the selectivity afforded by centrifugation, keeping bacteria in suspension while yeasts and other larger solids can sediment. The separation occurs due to the density difference between bacteria and yeast, the latter being removed from the supernatant due to their lower density. The partial removal of bacteria, the main contaminant, is a fundamental factor for an effective fermentation. ... [Pg.54]

Single microbes produce a very small metabolic heat of 1-3 pW per cell, which cannot be detected even with the most sensitive calorimeter. But the exponential replication of bacteria in culture allows their detection in sensitive so-called microcalorimeters. To decide whether a product is infected or not, it is sufficient to put it in a calorimeter vessel under ideal growth conditions at 37 °C. If the material is aseptic, no signal will develop, but in the presence of germs, an exothermic heat flow rate will be measured. To identify the different relevant bacteria, it is necessary to follow the growth behavior of the culture and see whether they can be distinguished from one another. Furthermore, the detection limit (the minimum bacteria concentration) has to be determined, and the significance of the measurement for different contaminations has to be proved. [Pg.270]

A recently published book provides an excellent survey of issues that relate to contamination with endotoxins (present in both viable and nonviable bacteria), their released cell wall constituents, and also viable bacteria in the pharmaceutical industry [1]. It is important to know both the content of the work environment (e.g., indoor air) and the pharmaceutical products themselves. The former provides information on possible sources of microbial contamination and the latter the purity of the final commercial product (or precursors in various stages in its preparation). In some cases it is vital to know the actual bacterial species involved in contamination culture-based methods are standard microbiological techniques which were the focus of Jimenez [1] and thus will not be discussed further. Any contamination (e.g., with endotoxins), regardless of the species of origin, is of utmost of importance (e.g., in determining the safety of a batch of antibiotics to be administered intravenously). This is determined optimally by non-culture-based methods. [Pg.534]

When developing activities involving cell lines carrying pathogens or primary cultures derived from infected animals, there is a potential risk of operator infection. Viruses present the highest contamination risk, but many bacteria, fungi, mycoplasmas and parasites can also be harmful to the operator. [Pg.30]

Consider that if 10 ml of a cell suspension is removed from a vessel it is replaced by 10 ml of air. It is therefore essential to reduce airborne contamination to a minimum. In an undisturbed room bacteria and fungal spores rapidly settle to the floor or the bench, and hence regular cleaning of the floor and bench with antiseptic solutions is required. The floor of the work room should be free of cracks and should be cleaned daily with a disinfectant solution. The work bench should be swabbed down before and after each use with a solution of 70% ethanol. This also serves to kill cultured cells which may have been spilt and hence prevents their transfer to other cultures (see 2.2). [Pg.168]


See other pages where Bacteria cell culture contamination is mentioned: [Pg.1659]    [Pg.246]    [Pg.104]    [Pg.439]    [Pg.222]    [Pg.24]    [Pg.1]    [Pg.49]    [Pg.44]    [Pg.13]    [Pg.29]    [Pg.50]    [Pg.6]    [Pg.52]    [Pg.47]    [Pg.2140]    [Pg.218]    [Pg.746]    [Pg.854]    [Pg.2126]    [Pg.104]    [Pg.164]    [Pg.225]    [Pg.294]    [Pg.296]    [Pg.142]    [Pg.71]    [Pg.102]    [Pg.135]    [Pg.143]    [Pg.409]    [Pg.36]    [Pg.323]    [Pg.157]    [Pg.127]    [Pg.655]    [Pg.172]    [Pg.507]    [Pg.142]   
See also in sourсe #XX -- [ Pg.26 , Pg.27 , Pg.28 ]




SEARCH



Bacteria cell culture

Bacteria cells

© 2024 chempedia.info