Chemistry: molecular biology and microbiology – Micro-organism – per se ; compositions thereof; proces of...
Reexamination Certificate
2000-05-23
2003-09-30
Tate, Christopher R. (Department: 1651)
Chemistry: molecular biology and microbiology
Micro-organism, per se ; compositions thereof; proces of...
C435S252000, C435S254800, C435S325000, C435S355000, C435S420000
Reexamination Certificate
active
06627426
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally methods for reducing, substantially reducing or eliminating adventitious agents (such as viruses, bacteria, mycoplasma, and non-cellular compounds such as proteins that result in acute or chronic toxicity/disease (i.e. prions)) in any sample (including liquid or dry samples). Thus, the invention relates to sterilization or substantial sterilization of such samples. More specifically, the present invention provides liquid and dry powder cell culture reagents including nutrients or ingredients utilized by cells in cell culture, and to nutritive medium formulations produced by such methods, particularly cell culture medium formulations comprising all of the necessary nutritive factors that facilitate the in vitro cultivation of cells. Such nutrients or ingredients may comprise one or more proteins, carbohydrates, lipids, amino acids, vitamins, nucleic acids, DNA, RNA, trace metals and buffers either alone or in combination. The invention also relates to liquid and dry powder media supplements, such as liquid or dry powder blood derived products such as sera (e.g., fetal bovine serum or other animal (i.e. porcine, horse, fish, etc.) or human origin sera) produced by the methods of the invention. The invention also relates to liquid and dry powder buffer formulations and media subgroups produced by the methods of the invention. The present invention also relates to kits containing samples produced by the invention, particularly cell culture reagents such as nutrients, media, media supplements, media subgroups, as well as methods for cultivation of prokaryotic and eukaryotic cells using these cell culture reagents.
BACKGROUND OF THE INVENTION
Cell Culture Media
Cell culture media provide the nutrient necessary to maintain and grow cells in a controlled, artificial and in vitro environment. Characteristics and compositions of the cell culture media vary depending on the particular cellular requirements. Important parameters include osmolality, pH, and nutrient formulations.
Media formulations have been used to cultivate a number of cell types including animal, plant, yeast and prokaryotic cells including bacterial cells. Cells cultivated in culture media catabolize available nutrients and produce useful biological substances such as monoclonal antibodies, hormones, growth factors, viruses and the like. Such products have therapeutic applications and, with the advent of recombinant DNA technology, cells can be engineered to produce large quantities of these products. Thus, the ability to cultivate cells in vitro is not only important for the study of cell physiology, but is also necessary for the production of useful substances which may not otherwise be obtained by cost-effective means.
Cell culture media formulations have been well documented in the literature and a number of media are commercially available. In early cell culture work, media formulations were based upon the chemical composition and physicochemical properties (e.g., osmolality, pH, etc.) of blood and were referred to as “physiological solutions” (Ringer, S.,
J Physiol.
3:380-393 (1880); Waymouth, C., In:
Cells and Tissues in Culture
, Vol. 1, Academic Press, London, pp. 99-142 (1965); Waymouth, C.,
In Vitro
6:109-127 (1970)). However, cells in different tissues of the mammalian body are exposed to different microenvironments with respect to oxygen/carbon dioxide partial pressure and concentrations of nutrients, vitamins, and trace elements; accordingly, successful in vitro culture of different cell types may require the use of different media formulations. Typical components of cell culture media include amino acids, organic and inorganic salts, vitamins, trace metals, sugars, lipids and nucleic acids, the types and amounts of which may vary depending upon the particular requirements of a given cell or tissue type.
Typically, cell culture media formulations are supplemented with a range of additives, including undefined components such as fetal bovine serum (FBS) (10-20% v/v) or extracts from animal embryos, organs or glands (0.5-10% v/v). While FBS is the most commonly applied supplement in animal cell culture media, other serum sources are also routinely used, including newborn calf, horse and human. Organs or glands that have been used to prepare extracts for the supplementation of culture media include submaxillary gland (Cohen, S.,
J. Biol. Chem.
237:1555-1565 (1961)), pituitary (Peehl, D. M., and Ham, R. G.,
In Vitro
16:516-525 (1980); U.S. Pat. No. 4,673,649), hypothalamus (Maciag, T., et al.,
Proc. Natl. Acad. Sci. USA
76:5674-5678 (1979); Gilchrest B. A., et al,
J. Cell. Physiol.
120:377-383 (1984)), ocular retina (Barretault, D., et al.,
Differentiation
8:29-42 (1981)) and brain (Maciag, T., et al.,
Science
211:1452-1454 (1981)). Cell culture media may also contain other animal-derived products, including but not limited to blood-derived products (e.g., serum, albumin, antibodies, fibrinogen, factor VIII, etc.), tissue or organ extracts and/or hydrolysates (e.g., bovine pituitary extract (BPE), bovine brain extract, chick embryo extract and bovine embryo extract), and animal-derived lipids, fatty acids, proteins, amino acids, peptones, Excyte™, sterols (e.g., cholesterol) and lipoproteins (e.g., high-density and low-density lipoproteins (HDLs and LDLs, respectively)). Cell culture media may also contain specific purified or recombinant growth factors for example: insulin, fibroblast growth factor (FGF), epidermal grouch factors (EGF), transferrin, hematopoietic growth factors like erythropoietin. IL, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, etc., colony stimulating factors like G-CSF, GM-CSF, histotypic specific growth factors like neural growth factors, specific regulators of cAMP or other signal transductive pathways etc. These types of supplements serve several useful functions in cell culture media (Lambert, K. J. et al., In:
Animal Cell Biotechnology
, Vol. 1, Spier, R. E. et al., Eds., Academic Press New York, pp. 85-122 (1985)). For example, these additives provide carriers or chelators for labile or water-insoluble nutrients; bind and neutralize toxic moieties; provide hormones and growth factors, protease inhibitors and essential, often unidentified or undefined low molecular weight nutrients; and protect cells from physical stress and damage. Thus, animal derived products are commonly used as relatively low-cost supplements to provide an optimal culture medium for the cultivation of animal cells.
Unfortunately, the use of such animal derived components or nutrients in tissue or cell culture applications has several drawbacks (Lambert, K. J., et al., In:
Animal Cell Biotechnology
, Vol. 1, Spier, R. E., et al., Eds., Academic Press New York, pp. 85-122 (1985)). Foremost is the potential to contaminate tissue or cell cultures with adventitious agents or toxins. Indeed, supplementation of media with animal or human derived components may introduce infectious agents (e.g., mycoplasma and/or viruses) or toxins which can seriously undermine the health of the cultured cells when these contaminated supplements are used in cell culture media formulations, and may result in the production of biological substances (e.g. antibodies, hormones, growth factors etc.) which are contaminated with infectious agents or toxins. Thus, contamination of cell or tissue cultures with adventitious agents or toxins may pose a health risk in cell therapy and in other clinical applications. A major fear is the presence of non-cellular soluble or insoluble proteins or other classes of bioactive components that may have disease pathogenesis, and in particular the presence of prions causing spongiform encephalopathy in humans or animals.
Thus, there exists a current need to reduce or eliminate adventitious agents (e.g. infectious agents) and toxins from cell culture reagents (e.g. nutritive media, media supplements, media subgroups, buffers and any nutritive components or solutions which may be found in cell culture media including proteins, carbohydrat
Biddle William C.
Bulera Thomas E.
Dadey Barbara M.
Fike Richard M.
Flood Michele
Invitrogen Corporation
Sterne Kessler Goldstein & Fox P.L.L.C.
Tate Christopher R.
LandOfFree
Methods for reducing adventitious agents and toxins and cell... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods for reducing adventitious agents and toxins and cell..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for reducing adventitious agents and toxins and cell... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3080389