Reference cell lines controls

In certain cases, serum (fetal bovine serum—FBS) is added to promote the growth of cells. However, the bovine spongiform encephalopathy (BSE) problem has necessitated tight control on the quality of FBS (refer to Exhibit 10.12). This increases production and downstream processing costs. For new cell lines being developed, serum-free and protein-free media are used to circumvent the possibility of virus contamination from animal sources and the variation that may arise from use of serum from animal herds. 

The IC50 values are expressed as meaniS.D. of three different determinations per experiment SI, the Selectivity Index, is defined as the ratio of the CC50 value determined on the mammalian cell line to that of the IC50 value determined on the CQ-sensitive P. falciparum (D6). Two reference drugs, chloroquine and artemisinin, are included as positive controls and their IC50 values are given in ng/ml. nd not determined. 

Use of Complex Standards for Cell Proteins and Two-Dimensional Electrophoresis. One of the more widely-used cell lines chosen as a reference standard is the lymphoblastoid cell line GM607, derived from a normal individual and available from the Human Genetic Mutant Cell Depository, Camden, NJ 08103. This cell line may be grown in defined media, labeled with a radioactive tracer, and reproducibly separated in a 2-DE system. Heat shock proteins may readily be isolated and visualized from this cell line, as shown by Anderson et al. (42). For serum, a reference preparation for serum proteins is available as a certified reference material prepared and assayed by the College of American Pathologists (CAP) and by the U. S. Centers for Disease Control. A widely available human serum standard is that provided by the National Bureau of Standards as SRM 909. If sufficient interest from the user community is evident, a full electrophoretic characterization of this material can be included in the documentation. If the amount of selected standard proteins loaded on a gel is known, "relative" quantification of similar proteins could be obtained. In addition, the National Bureau of Standards could serve as an impartial evaluator of potential national standards (e.g. molecular weight standards, "tie-point" proteins, and Isoelectric point standards) to assess suitability and stability. 

A TMA can be constructed from cultured cell lines. These cell line samples can serve as control samples because they have been extensively used in the literature and their profile for the marker of interest might be well documented (10,11,12). The cell line pellets are processed in a manner similar to that for routine surgical pathology tissue. This is important because it eliminates any variability related to fixation protocols with reference to immunohistochemical reactivity and sample viability. Use of a resin-based approach has also been described (13). This technique provides excellent morphology and minimizes variability of marker expression related to fixation protocols. 

The utilization of the photometric synthesis control [95] was already mentioned in Sect. 3.1.3, 3.2.4, and 3.3.6 (Fig. 61). The system consists of a two-channel flow photometer with reference cell technique operating on two wavelengths. It is connected to a continuous line recorder with fifteen times automatic scale expansion at constant sensitivity and a graphic integration supplement. The photometer reference flow cell of a wide inner diameter has an optical path of 5 mm. It is inserted between the metering system of the synthesizer and the centrifugal reactor and allows a flow rate of 5 to 10 liters/hour. 

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