Three-plate test

Another test that has been adapted by the Center for Veterinary Drug Residues, Saskatoon, Canada, to screen muscle samples from imported carcasses is the cube inhibition test (CIT) (83). Tissue preparation is similar to that in the German three-plate test in that tissue cubes are placed on seeded media. The organism is Bacillus subtilis, two different agar plates are used, and incubation is carried out at 37 C for 18-24 h. 

Antibacterial German three-plate test EEC four-plate test CHARM II test New Dutch kidney test STOP CAST FAST CHARM farm test ATP test... 

The NKDT test is sensitive to residues of -lactams, tetracyclines, and macrolides. It is more sensitive to sulfonamides than the German three-plate test or the EU four-plate test, but it is relatively insensitive to aminoglycosides. With respect to MRLs set for liver or kidney, the NKDT is too insensitive for aminoglycosides, sulfonamides, and macrolides. One analyst can complete 150-200 tests per day. Due to the high ratio of residue levels in preurine and muscle, a negative result of this test implies that residue levels in muscle are below the limit of detection. 

Twenty-four hundred grams (25.6 mol) of phenol, 1645 g of 37 wt % formaldehyde (20.3 mol), and 30 g (0.33 mol) of oxalic acid were charged to a 5-L, three-necked resin kettle. The mixture was stirred and refluxed until the distillate was free of formaldehyde (1-3 h) then water was distilled from the mixture until the resin temperature reached 154°C. The viscosity of the resin at this point at 150°C was such diat 105 s was required for flow in an inclined plate test. The pressure was slowly reduced while a slow current of nitrogen was bubbled through the resin, and the mixture was heated to 175°C at 6 mm Hg. Approximately 6 wt % phenol was recovered then the resin was poured into an aluminum dish and cooled. The resin had a melt viscosity of 510 s at 150°C. 

Three useful tests have been used to evaluate the working and setting properties of experimental cements. These are the parallel plate plas-tometer, the penetrometer and the oscillating rheometer. They are described in the following sections of this chapter. 

By using an in vitro UV-crosslinking approach, bacteria-purified recombinant CPEB3 has been demonstrated to interact with the 2> UTR of GluR2 mRNA. To test whether this interaction occurs in vivo, hippocampal neuron cultures are ultraviolet (UV)-irradiated, homogenized, and immunoprecipitated with CPEB3 IgG or nonspecific IgG (Huang et al, 2006). Three plates of 2- to 3-week-old cultured neurons ( 6—8 million... 

Reversion Tests Background. There are several excellent references describing the background and use of bacteria for reversion tests (Brusick, 1987 Gatehouse et al., 1990). Three different protocols have been widely used plate incorporation assays, treat and plate tests, and fluctuation tests. These methods are described in detail in the following sections. Fundamental to the operation of these tests is the genetic compositions of the tester strains selected for use. 

Apart from detection, some microbial inhibitor tests including the three-plate and the six-plate tests are further suitable for tentative confirmation of... 

Since 1974, Bacillus subtilis EGA has been officially employed as the test organism in the German Hemmstoff test to detect residues of tetracyclines, -lactams and aminoglycosides in kidney and muscle tissues with high sensitivity (72). Macrolides can be also detected, but to a lesser extent, whereas chloramphenicol and sulfonamides are difficult to detect. For better detection of sulfonamides, a modification of this test, the German three-plate inhibition test, was developed. This test is based on the same test organism but uses three pH values (6, 8, and 7.2), with the addition of trimethoprim. The pH relationship between the three... 

The four-plate test was initially based on the German Hemmstoff-test with an additional plate of Sarcina lulea at pH 8.0, designed for the detection of lower levels of macrolides, and a fourth plate of Escherichia coli at pH 7.2 for the detection of sulfonamides (74,75). The modified version adopted by the European Community for screening carcasses is based on three plates with Bacillus subtilis BGA at pH values of 6.0, 8.0, and 7.2 with added trimethoprim, respectively, and a fourth plate with Micrococcus luteus NCTC 8340 at pH 8.0 (74). This test as described elsewhere (76) is intended to detect residues of -lactams, tetracyclines, aminoglycosides, sulfonamides, and macrolides in muscle tissue of slaughtered animals, without any prior extraction or cleanup. 

In April 1988, the new kidney Dutch test (NKDT) replaced the Micrococcus (formerly Sarcina ) luteus kidney test. The NKDT is an one-plate test based on examination of the urine present in the renal pelvis by means of paper discs inserted in the renal pelvis (104). The test organism is Bacillus subtilis BGA and incubation is performed for 13-18 h at 37 C. The kidney is incised, and four paper discs are inserted and left there for 30 min. Two paper disks are placed diagonally on the surface of the test plate, and three control disks containing 0.5 g oxytetracycline, 0.05 g sulfamethazine, and 0.5 g tylosin are also placed in the middle of the plate. If both sample inhibition diameters are equal to or... 

Figure 2. Comparison of mutagenic activity in lyophilized and XAD-concentrated drinking water. The sampling 7000-fold concentration with either XAD-4/8 (XAD) or freeze-drying (FD) XAD-4/8 elution with acetone (neutral fraction) freeze-drying elution successively with acetone, ether, and DM SO and subsequent mutagenicity testing with strains TA98 and TA100 were as described in Materials and Methods. Each point represents the average of three plates, and 0.2 mL of concentrate corresponds to 1.4 L of water per plate.

Janssen and Eddy(41) have given a semiquantitative estimate of the influence of systematic chemical modifications on analgesic potency in mice and rats of a series of N-substituted norpethidines and reversed esters of pethidine. Their estimates, based on the results of the hot-plate test obtained in three separate laboratories, are illustrated in Scheme 6.3. 

Three standardized atmospheric galvanic corrosion tests are the plate test, the wire-on-bolt test, and the disk test. The plate test, described in ISO Standard IS07441, Determination... 

FIGURE 57.5 Peak temperature vs. number of cycles to failure by PTH barrel (solid bars) or corner (dashed bars) cracking in three different tests. Calculated lines are shown for comparison. Results are for pyrophosphate copper and FR-4. Other parameters are total strain energy required to cause fracture, 50 J/cm hole radius, 0.45 nun distance from hole center to free end, 0.8 mm plating thickness, 0.02 mm distance from hole center to pad edge, 0.8 mm board thickness, 2 mm. Results from Ref 2. 

Three special tests were performed with the actual pump. For these tests the existing test rig "Dnom 500" was used into which the actual pump is placed for performance of acceptance tests after manufacturing. Resistance of the primary circuit is ensured by the special orifice plate. The test rig was upgraded ... 

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