Growth inhibition assay

TABLE 5.1 IC50 (nM) Values from Cell-Growth Inhibition Assays... 

FIGURE 5.35 Growth inhibition assay of three human cancerous cell lines, with dendritic prodrug 38 in the presence ( ) and absence ( ) of PGA cells were incubated for 72 h. 

Nitroheteroarenes continue to attract research activity. A series of 5-nitro-2-furyl derivatives were evaluated for in vivo efficacy against T cruzi [64] and an improved toxicity profile. Compound 65 showed a good efficacy profile in vivo and better acute toxicity profile when compared to nifurti-mox. A series of 5-nitroindazoles, represented by 66 (IC50 = 7.4 iM), were reported as having activity similar to nifurtimox (IC50 = 3.4 iM) in a growth inhibition assay [65]. 

Sugiyama, M., Itagaki, H. and Kato, S. (1994) Photohemolysis test and yeast growth inhibition assay to assess phototoxic potential of chemicals, in Alternative Methods in Toxicology (eds A. Rougier, A.M. Goldberg and H.I. Maibach), Mary Arm Liebert, Inc., NY, 10, pp. 213-221. 

More versatile than the growth-inhibition assays and potentially applicable to determining the presence of different antibiotic residues in different matrices are the microbial receptor CHARM I and II test assays (19, 20). The Charm I test, developed exclusively for -lactams in milk, constitutes the first rapid test recognized by The Association of Official Analytical Chemists (AOAC) with a test time of 15 min (19). The speed and sensitivity of this test permitted testing of milk tankers before they unloaded at the processing plant (21). In 1984-1985, the CHARM I test was further developed to test for antibiotics beyond -lactams to include tetracyclines, sulfonamides, aminoglycosides, chloramphenicol, novobiocin, and macrolides. The extended version has been referred to as CHARM II test. 

Besides physicochemical methods, the use of microbiological growth-inhibition assays to test meat and milk for the presence of antibiotics residues is popular over a long period of time. These tests use antibiotic-sensitive bacterial reporter strains, such as Bacillus subtilis and Bacillus stearothermophilus var. calidolactis. These bacteria are inoculated under optimal conditions with and without sample. After culturing, results are read from visible inhibition zones or from the color change of the bacterial suspension in agar gels [6]. 

Chromotest) Selenastrum capricornutum (micro-algal growth inhibition assay) Ceriodaphnia dubia acute immobilization test Ceriodaphnia dubia chronic reproduction test (Costan et al., 1993). ... 

Vibrio fischeri, Microtox light inhibition test Pseudokirchneriella subcapitata, micro-algal growth inhibition assay Daphnia magna, acute immobilization test Ceriodaphnia dubia, chronic reproduction and survival test Thamnocephalus platyurus, Thamnotoxkit lethality assay. 

ALG Pseudokirchneriella subcapitata (micro-algal growth inhibition assay) DM Daphnia magna acute immobilization test CER Ceriodaphnia dubia chronic reproduction and CES Ceriodaphnia dubia survival test. 

Desmodesmus subspicatus, micro-algal growth inhibition assay (DEV L33, 1991). 

Lemna minor, plant growth inhibition assay (Feiler and Krebs, 2001) ... 

In principle, any battery of bioassays can be employed, but small-scale toxicity tests are preferred because of their performance output (Wells et al., 1998). It is highly desirable that bioassays used were part of the initial bioassay battery (prerequisite step) that proved to be sufficiently sensitive in the WASTOXHAS approach. Examples include the Microtox light inhibition test (Vibrio fischeri) and the microalgal growth inhibition assay (Selenastrum capricornutum ) that were found suitable for two tested wastes (see Section 7). 

In several growth inhibition assays the unnatural ( -enantiomer was as active as (+)-ABA. However, (-)-ABA was much less active than (+)-ABA in closing stomata of detached barley leaves (see 3). When assayed in darkness (to avoid photoisomerization) t-ABA was completely inactive (2). 

Because of their well-recognized physicochemical properties (relatively high hydrophobicity, cationic character, and short length) reversed-phase, size-exclusion, and cation exchange chromatographies are particularly appropriate to purify bioactive peptides from the immune system of invertebrates. The sensitivity of HPLC, MS, Edman degradation, and liquid growth inhibition assays allow one to use from narrow (e.g., 2.1-mm internal diameter) down to micro-or nano-columns. 

It is better to label the PRPs at the C-terminus. In our experience, if the peptide is labelled to the N-terminus we often noticed a significant decrease in antimicrobial activity. Before using labelled PRPs, it is in any case advisable to check whether this chemical modification has altered its antimicrobial activity compared with that of the unmodified molecule by both MIC and growth inhibition assays (see Subheading 3.5). In our experience the addition of the BODIPY to the C-terminus of Bac7(l-35) did not modify its antibacterial properties. 

Fig. 3. Cross-resistance profiles for the 41M/41McisR, CH 1/CH1 c sR and A2 780/A2780cisR pairs of human ovarian-carcinoma cell lines for cisplatin itself carboplatin, tetraplatin (1,2-diaminocyclohexane)tetrachloroplatinum(IV)), JM216, JM118 (the major metabolite of JM216) andAMD473. Resistance Factor = IC50 resistant/parent cell line. Drug exposure was for 96 h, sulforhodamine B growth-inhibition assay, bars = SEM, n = 3-4.

Comments Environment Canada (1992b) has outlined a test protocol for a miniaturised alga growth inhibition assay. The application of 96-well microtiter plates facilitates the measurement of a high number of samples. 

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