Laboratory methodologies

Bacteria are the only pathogens routinely tested for in food samples, whereas viruses and parasites are typically tested in stool specimens of persons infected after food consumption. The food processor tests for specific types of bacteria and can choose among culture tests, gene probes, manual immunoassays, and instruments (automated immunoassays) (Kroll, 2001). 

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Hughes, GJ. and Frutier, S. 1990 Amino acid analysis protocols, possibilities, and pretensions. In Fini, C, Floridid, A., Finelli, V.N. and Wittman-Leibold, B., eds., Laboratory Methodology in Biochemistry Amino Acid Analysis and Protein Sequencing. Boca Raton, FL, CRC Press, Inc. 44-61. 

Panepinto, L. (1986). Laboratory methodology and management of swine in biomedical research. Swine Biomed. Res. 1 97-109. 

Fini, C., Floridi, A. and Finelli, V.N. (1989) Laboratory methodology in biochemistry amino acid analysis and sequencing, CRC Press, UK. 

The BCS guidance allows for the use of tissue and cell culture methods to classify a drug substance as high or low permeability [6], The differences in laboratory methodologies for these assays suggest that a basic outline be... 

Once an application has been accepted for evaluation, the Pharmaceutical Chemistry Evaluation Section, Toxicology Section and Clinical Evaluation Units evaluate the Module 3, 4 and 5 data, respectively. For applications relating to products of biological origin, a second copy of the Module 3 data is also evaluated by the TGA Laboratories (TGAL) Branch, which evaluates aspects such as laboratory methodology, method validation and shelf-life. 

The catecholamines are a group of hormones secreted by the adrenal medulla. The major urinary metabolite of norepinephrine and epinephrine is vanillylmandelic acid (VMA). Urinary levels of VMA are considerably higher than those of total catecholamine. From the standpoint of laboratory methodology, VMA estimation is preferable to total catecholamine estimation, although it is not a simple procedure. VMA has been shown to be elevated in some patients who had phenochromocytoma and normal urinary catecholamines, even though patients with neuroblastoma have a normal VMA level and elevated catecholamine levels. 

P. Maijanovic, M. McGarvey, R.B. McKay, Development of laboratory methodology to determine flow properties of organic pigment... 

The major objective of this chapter is to report on preliminary laboratory investigations that simulated pesticide treatments on historic type textiles and assessed the relative safety or potential damage commensurate with their use. This experimentation will demonstrate laboratory methodology and report on color or strength changes that may ensue with pesticide treatment. It also is hoped that others will recognize the need for further related work and expanded research efforts in this fruitful and neglected area will result. 

This retardation is caused by adsorption on clays and organic materials. The adsorption capacity is in turn a function of the surface area and availability of these materials to the adsorbing species in question. In real soils, and especially those of sedimentary origin, the adsorbant components are to be found as discrete lenses of low permeability rather than as an evenly distributed phase as is essentially assumed in the laboratory methodologies for determining the retardation factors. In these lenses penetration to the bulk of the adsorption sites is restricted to diffusion and the small residual convection fluxes. 

Analysis is an integral part of research, clinical, and industrial laboratory methodology. The determination of the components of a substance or the sample in question can be qualitative, quantitative, or both. Techniques that are available to the analyst for such determinations are abundant. In absorption spectroscopy, the molecular absorption properties of the analyte are measured with laboratory instruments that function as detectors. Those that provide absorbance readings over the ultraviolet-visible (UV-vis) light spectrum are commonly used in high-performance liquid chromatography (HPLC). The above method is sufficiently sensitive for quantitative analysis and it has a broader application than other modes of detection. 

Third, assays need to describe methods used for obtaining minimal detection limits (e.g., mean plus 3 SD of 20 replicates of a zero calibrator) and total imprecision, describing at what concentration a 10% CV is attained. Preanalytical factors that should be described include the effects of storage time and temperature, glass versus plastic tubes and gel separator tubes, and the influence of anticoagulants and whole blood measurements. As more assay systems are devised for POCT, the same rigors applied to the central laboratory methodologies need to be adhered to by the POCT systems. 

Several isotopic methods have been used to accurately estimate the free hormone fraction, including equilibrium tracer dialysis, ultrafiltration, Sephadex chromatography, and polyacrylamide gel filtration. However, these techniques are very cumbersome and time consuming for routine clinical use and, with the exception of equilibrium tracer dialysis, have found little practical application. Unfortunately the free hormone fraction as estimated in normal sera by equilibrium tracer dialysis varies substantially among laboratories. Methodological difficulties include the presence of residual impurities in the tracer, the temperature and duration of dialysis, tlie adsorption of tracer by components of the dialysis system, and the in vitro generation of free fatty acids. ... 

The first part of the laboratory methodology for study of enhanced degradation Involved use of a rapid degradation assay by which an Idea of the rate of insecticide degradation could be obtained for a large number of soils. The soils for this assay were collected during the fall from Iowa cornfields with known histories of Insecticide use. In some cases the soils collected were specifically from fields in which an insecticide had been used for several years and no longer provided suitable control of soil insect pests. In these cases a separate soil was also collected from an adjacent field or from the field fencerow. 

The second component of the laboratory methodology for study of enhanced degradation involved a more intense investigation of the soil degradation of insecticides identified as suspect from the rapid degradation assay (carbofuran, isofenphos, fonofos) as well as 2 additional insecticides (cloethocarb, chlorpyrifos). The degradation... 

Asymmetric synthesis, the selective generation of new chirality elements (as one definition goes), has developed from a specialty pursued by outsiders to an art cultured by some learned ones, and now may be considered a standard laboratory methodology for everybody s use. This development has taken place exponentially (explosively ) in the last two decades, triggered by a number of circumstances. Also the practitioners of pharmaceutical, vitamin, and agro synthesis need to produce enantiopure, rather than racemic active compounds (for registration ). 

Pyridine is prepared commercially by the gas-phase, high-temperature reaction of crotonaldehyde, formaldehyde, steam, air, and ammonia over a silica-alumina catalyst in 60-70% yield. We will illustrate some of the common laboratory methodologies for the construction of substituted-... 

We have successfully demonstrated the principle of selective catalytic reductive deoxygenation of vicinal diols. The challenges inherent to this transformation have hindered development of carbohydrate-based organic feedstock chemistry. While there remain aspects of our chemistry that keep it a laboratory methodology, there is now a clear route to development. 

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