Agar diffusion test

The first study was performed by Venturini [97, 98] in both rats and dogs by using a microbiological assay (i.e. agar diffusion test and S. aureus 209 P FDA as test organism). Conversely from rifampicin, whose serum levels were already detectable 30 min after the administration and still measurable after 48 h, only trace amounts (i.e. 0.2 pg/ml) of rifaximin were detected in serum of fed rats 4 h later (fig. 6). The amount of detectable antibiotic was reduced by 50% in fasted animals. Similar results have been obtained in dogs after oral administration of 25 mg/ kg of both rifamycin derivatives [97, 98], No detectable amount of rifaximin was found in serum at any time. 

Agar-diffusion tests with the anti-isomaltose, myeloma protein and several dextran preparations showed that the protein does indeed combine with a number of dextrans. Results of gel electrophoresis of the sample showed that the purified myeloma protein consisted of several multimolecular forms.107 This observation is at variance with a report that the W3129 myeloma protein isolated from the same type of serum was homogeneous.168 Additional studies are needed in order to establish whether the anti-isomaltose, myeloma protein is synthesized as a homogeneous protein or in multimolecular form. 

To overcome this problem, an agar diffusion test has been developed to detect chloramphenicol residues in the urine of slaughtered animals (87). The principle of the test is based upon incorporation of -glucuronidase in an agar medium shown with Bacillus subtilis. With this test, the glucuronide of chloramphenicol, which is the major metabolite in urine, is hydrolyzed and the antibacterial activity is demonstrated according to the usual microbiological detection assays. 

That both components were antibodies was established by agar diffusion tests with these preparations and solutions of the glycan performed in the usual manner. The results of the agar diffusion tests are shown in Figure 3, right plate. The two preparations of antibodies have been designated as anti-galactose (anti-gal) antibodies and anti-lactose (anti-lac) antibodies and some of the properties of the two sets of antibodies are described in a later section. 

The sedimentation constants and molecular weights calculated from ultracentrifugation data for both types of antibodies were 7s and 150,000 respectively. Agar diffusion tests with goat antisera against rabbit IgA, IgG and IgM showed that both antibody sets are of the IgG immunoglobulin type (29). 

The three antisera and the anti-glycosyl antibodies isolated from these antisera have been tested in agar diffusion tests for cross-reactivity with the three iirmunogens and with bovine serum albumin. These results are shown in Figure 8. 

Sepharose and elution with lactose (Fig. 23). The UV-absorbing fraction that was eluted with the lactose solution was collected and the protein precipitated by addition of an equal volume of saturated ammonium sulfate. On refrigeration of the sample overnight, a white precipitate formed. This precipitate was collected by centrifugation and redissolved in 0.2 mL of 0.02 M phosphate buffer of pH 7 in saline. The agar-diffusion test shown in the inset of Fig. 23 showed that high-titer antibodies were produced that formed a precipitin complex with the antigen. Several affinity runs were made. The antibody samples were combined and lyophilized. The yield of anti-lactose antibody was 50 mg from 20 mL of serum. 

This test is used to evaluate the toxicity of a material in vitro or an extract of a material used in a device. Several different tests have been used and have produced a spectmm of biocompatibility assessments on the same material (20-22). The tests used measure the viability of cells in contact with a material or an extract of a material. A variety of cell lines can be used however, a modified fibroblast line is usually the gold standard. Some tests used include 1) direct cell culture, 2) agar diffusion testing, 3) filter diffusion testing, and 4) barrier testing (22). 

Three in vitro biological tests exist the agar diffusion test, the direct contact test, and the elution test. Each test evaluates the interaction of the polymer with... 

The Epsilometer test (E-test AB Biodisk, Solna, Sweden) combines the benefits of quantitative MIC test methods with the ease of agar diffusion testing. The E-testis aplastic strip impregnated with... 

L18. Lee, G., and Robinson, J. C., Agar diffusion test for serum cholinesterase typing and... 

Delivery of antibiotics from such formulations resulted in suppressed bacterial growth, and thus antibacterial activity, in an in vivo rabbit model. Furthermore, these formulations have proven to be effective in an agar diffusion test, direct contact test, mouse model, and rabbit osteomyelitis model without disturbing normal bone ingrowth. 

In 1944, Foster et al. were one of the first groups to develop an agar diffusion test for the determination of penicillin in liquid samples. Agar seeded with Bacillus subtilis spores was added to a petri dish. Sterile glass cups were then filled with liquid samples containing different concentrations of penicillin and placed on the... 

Okerman et al. compared the performance of a Tetrasensor with three microbial inhibition assays for the analysis of tetracycline antibiotics in tissue. The group concluded that when large numbers of samples have to be analyzed without the requirement for immediate results, classical agar diffusion tests with thin plates and performed as prescribed for the EPT still seem the most economical choice. However, the receptor-based test Tetrasensor was recommended for use in official surveys and also in cases when immediate results are required. Unlike the inhibition tests, this receptor test does not require a well-equipped laboratory for use and is more suited for the meat industry. ... 

Agar diffusion tests seml-quantltatlve -Demonstrated zone of Inhibition and around the treated fabric samples... 

This effect can also be realized for specific bacteria namely Gram-positive S. aureus and Gram-negative E. coli in agar diffusion test [128] as demonstrated in Fig. 19.46. 

In vitro Agar diffusion test L-929 mammalian fibroblast cells Prepare monolayer cell culture with medium containing agar, place the flat surface of samples and controls in contact with the agar surface Size of the zone around or under sample... 

Monolaurin (mono-ester of glycerol and lauric acid) is found in coconut oil and is claimed to have in vitro antibacterial and antiviral effects (Carpo et al., 2(X)7). Fabrics were finished with monolaurin and their antibacterial activity was examined according to the agar diffusion test (ISO 20645). The samples possessed antibacterial activity against S. aureus, but were not effective against E. coli (De Smet et al, 2014). Table 1.9 summarizes the antibacterial effect of textiles treated with different biobased antimicrobial products. The concentrations mentioned are dry weight concentrations (w/w) of the antibacterial additive onto the textile. 

Tests on extracts L929 elution test Neutral red uptake test Colony formation test 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and related tests Direct contact test Indirect contact test Agar diffusion test Filter diffusion... 

Among the testing methods used to characterize in vitro antimicrobial activity of essential oils, the three main methods turned out to be agar diffusion test, serial broth or agar dilution test, and... 

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