Specimens, storage

Pure ethanol, C2H5OH, is called absolute ethanol and is used in medicine as a solvent, specimen storage liquid and cleansing agent. It mixes well with water and can be easily diluted. This property is unusual for covalent organic compounds as they are usually insoluble and immiscible in water. The solubility here is because of the similarity between the OH in the water structure, HOH, and the alcohol C2H5OH. Medicinal solutions in alcohol are called tinctures . 

Saketos, M., Sharma, N., Adel, T., Raghuwanshi, M., and Santoro, N., Time-resolved im-munofluorometric assay and specimen storage conditions for measuring urinary gonadotropins. Clin. Chem. 40, 749-753 (1994). 

Type of container used for the specimen Specimen storage temperature (in °C)... 

We begin this section with discussions of the roles that workstations, instrument clusters, and workceHs have in laboratory automation, followed by discussions of specimen transportation, automated specimen processing, automated specimen sorting, and automated specimen storage and retrieval subsystems. 

Automated capability to store and retrieve specimens on demand is an important aspect of automated specimen delivery systems. A few of the integrated systems described above (e.g, Beckman Coulter) offer specimen storage and retrieval modules as options in their systems. These robotic modules store specimens refrigerated in specific locations that are logged into a database maintained by the specimen delivery system. When a user requests a specific specimen to be retrieved, the robot is given commands to retrieve the specimen from the appropriate archived location and to route the specimen to the requested station using the specimen transportation system. 

Changes in the means of patient populations may be caused by multiple variables (see Chapters 16 and 17). Changes in the demographic and clinical characteristics of the patients, such as the ratio of males to females, the ratio of hospitalized patients to outpatients, or the presence of many specimens from a specialty clinic can alter the mean value. Similarly, changes in preanalytical conditions,such as tourniquet time and specimen storage, alter patient population means and can therefore be monitored by use of patient means. These variables are not monitored by those control procedures employing stable materials thus the patient mean procedures provide additional capabilities and should be used in conjunction with other control procedures. 

Specimen storage. Serum or plasma should be removed from ceils within 3 hours of venipuncture. Specimens can be stored for up to 3 days at 4 °C up to several weeks at -20 °C in a nonself-defrosting freezer and at -70 °C or lower for longer periods. 

Animal and human studies have demonstrated that endogenous GHB concentrations can rise post-mortem and under inappropriate specimen storage conditions. Doherty et al. (1978) observed an increase in the GHB concentrations in brain specimens after 6 h with a further increase if the specimens were left at room temperature. Snead et al. (1981) also observed an increase in GHB concentrations in CSF after 12 h of storage at room temperature. It was... 

In regard to the stability of the phenotype determined on fresh os stored serum or plasma, there are numerous observations that the chemical tests lead to the same phenotype after specimen storage in the frozen state. This is true of the enzymes produced by the Ej, E, E, E, E j, E j, and E genes. It is possible that some undiscovered variants may be missed because of changes occurring in the serum or plasma before it has been analyzed. Most investigators seem to disregard this possibility. 

Incorrect specimen storage. A bltMtd sample stored overnight before being sent to the laboratory will show fal.selv... 

If the analyte is very volatile (e.g., propane or butane) and a quantitative analysis is required, a blood sample should be collected directly into the headspace vial in which the analysis will be carried out. Many other volatile compounds are relatively stable in blood and other tissues if simple precautions are taken. In the case of blood, the container used for the sample should be glass, preferably with a cap lined with metal foil greater losses may occur if plastic containers are used. The tube should be as full as possible and should only be opened when required for analysis and then only when cold (4°C). If the sample volume is limited, it is advisable to select the container to match the volume of blood so that there is minimal headspace. An anticoagulant [sodium ethylenediaminetetraacetate (EDTA) or lithium heparin] should be used. Specimen storage between - 5 and 4°C is recommended and 1% (w/v)... 

Analysis of Chlorpromazine in Plasma Effect of Specimen Storage... 

It was previously stated that it is important to reduce the costs of surveys as much as possible, while still meeting objectives. Whether in situ or ex situ, the first consideration is the costs of the measurements themselves. These will vary from facility to facility, and depend on several factors such as whether there is a laboratory on-site, in which case specimen storage and transportation costs can be minimized. Costs also depend on site protocols, for example permitting procedures for excavation and handling of soil specimens. In any case, laboratory measurements tend to be more expensive than an... 

Not recommended for use exhibits low level of migration into fats/oils K Resin KR03 Phillips Specimen Storage containers with shelf life from several days to years... 

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