Resazurin test

An even simpler and perhaps more effective approach to the problem might be application of the resazurin test as applied in the milk industry for indirect estimation of bacterial population. Proctor and Greenlie (34) have suggested this application, and Wolford (38) has worked with it in a limited way. The test is based upon a color change involved in the reduction of the dye. The time required for reduction decreases with increase in bacterial numbers. Intensive investigation of this method and its application with respect to increasing its sensitivity, and correlation of reaction rates with bacterial population and quality characteristics of the product, might be of considerable value. 

Analytical methods can be defined as techniques to determine microbiological activity measured as a defined chemical reaction. Examples of such methods are the Resazurin test, the Ninhydrin test and the measurement of dehydrogenase activity. 

Resazurin test The resazurin test is much quicker than the methylene blue test. Milk is mixed to aerate it and 10 ml placed in a tube. Resazurin dye solution (made from a standard tablet) is added, the tube sealed, inverted twice, and incubated at 37.5 C for 10 min. If actively reducing bacteria are present, the... 

With the recent development of reliable microbiological tests for acute toxicity determination, such as the Microtox test (Bulich et al. 1981) and the resazurin test (Thomson etal. 1986), convenient tools became available for the investigation of larger series of chemicals in relatively short time and independent of local biological species and environments. It has also been demonstrated that these tests are generally quite representative of such... 

Thomson, K., Liu, D. and Kaiser, K.L.E. 1986. A direct resazurin test for measuring chemical toxicity. Toxicity Assessment 1 407-418. 

L. Andreou, E. Comparison of the resazurin test, adenosite triphosphate in semen, and various sperm parameters. Hum. Reprod. 1994, 9,1688-1693. 

Fuse, H. Okumura, M. Kazama, T Katayama, T. Comparison of resazurin test results with various sperm parameters. Andrologia 1993,25,153-157. 

However, fullerene C60-modified surface is adequate for the adhesion and normal growth of cells in culture. Cells of the line MA-104 in the Eagle-MEM medium formed on fullerene film a normal monolayer. Cellular viability was assessed with the resazurin (Alamar Blue) reduction test. The dye resazurin is reduced by mitochondrial dehydrogenases of viable cells into the fluorescent product resorufin (maximum X = 530 nm, max X = 590 nm). The intensity of... 

Table 7.2 Cellular viability of MA-104 culture grown on fullerene on the surfaces (FoS) during 72 h. (resazurin reduction test)...

Strain K4 was tested in the absence of oxygen at various concentrations of glycerol (10,20,30,40 g L ).Two serum bottles were used with a modified Hungate technique one ofthe bottles contained resazurin and a reducing agent, namely cysteine-H Cl, and the other did not contain resazurin. The gas was analyzed by GC with TCD. 

Microtox Solid-phase test SDI Vibrio fischeri is added to a suspension of the test sample. Subsequently, the mixture is filtered using the device supplied with the kit, and the light emission of the supernatant is determined. The method is a further development of the acute luminescent bacteria test for aqueous samples. Contact test with Bacillus cereus DSM No. 351 Effects on the dehydrogenase activity of the test bacterium after an exposure time of 2 hours are investigated using resazurine reduction (Ronnpagel etal. 1995). 

Toxilrak has been used to determine toxicity in water samples. There is a report (Gupta and Karuppiah, 1995) in which they tested water samples from a river in Maryland using this method, Microtox , Ceriodaphnia dubia (a variation of the standard Daphnia test), and fliis test. Wifli four samples, they got comparable results. The Toxitrak test is not used extensively. Apparently die test follows the reduction of dye resazurin by cells of 5a-cillus cereus (Liu, 1989). 

Toxicity measurement this is a rapid test for biocide product selection, using resazurin. 

Eoote, R. H. Resazurin reduction and other tests of semen quality and fertility of bulls. Asian J. Androl. 1999,1, 109-114. 

Reddy, K. V. Bordekar, A. D. Spectrophotometric analysis of resazurin reduction test and semen quality in men. Indian J. Exp. Biol. 1999,37,782-786. 

Dart, M. G. Mesta, J. Crenshaw, C. Ericsson, S. A. Modified resazurin reduction test for determining the fertility potential of bovine spermatozoa. Arch. Androl. 1994,33,71-75. 

M. T. Marcoux, L. J. Sullivan, H. The resazurin reduction test provides an assessment of sperm activity. Fertil. Steril. 1991,56,743-746. 

Fig. 2 Map of 96-well plates as used for either resazurin or the PI assay. The outer wells are filled with 200 (iL of sterile distilled water shaded. On this plate setup 200 pL of test compound or control drug, usually at 200 pM, is added to the wells labeled Start, and a doubling dilution is carried out over the next 18 wells (whitdj. The final wells, marked with multiplication sign, do not receive any drug but are control for maximum growtti...

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