Tissue frozen

An LC-thermospray MS assay was used for the determination of FZD in porcine tissue. Frozen pulverized tissue was homogenized with MeOH McIlvaine buffer, and the supernatant was extracted with dichloromethane. The organic layer, evaporated and reconstituted in... 

In this chapter, we do not address the question of collection, storage, and sectioning of tissues. Frozen tissues (e.g., derived from surgical biopies), plastic- or paraffin-embedded tissue (bearing denaturation-re-sistant tintigenic determincints), cind, of course, cell suspensions can be analyzed with equivalent facility. 

Organics in mussel tissue Frozen powder-like homogenate 13... 

Sun, D.-W. and Li, B. 2003. Microstructural change of potato tissues frozen by ultrasound-assisted immersion freezing. Journal of Food Engineering 57(14) 337-345. 

Fig. 4.4 Cryostat. Use a cryostat to cut sections from tissue frozen on a chuck, (a) The chamber of a cryostat with the frozen tissue indicated by the black arrow. This tissue was frozen in a rectangular mold, (b) The chuck with the tissue is placed in the arm. (c) The excess O.C.T. is trimmed off with a razor blade by cutting into the block several times, (d). The trimmed frozen O.C.T. is removed with a razor blade cut from the top of the block, (e) The knife is adjusted into position very close to the block, but not touching. The block is advanced toward the block until sections are cut. (f) The anti-roU plate prevents cut sections from curling, (g) An alternative to the anti-roll plate is to use a fine paint brush to hold a section as it comes off the block, (h) Sections are picked up on microscopes slides, (i) Lower the bottom of the slide until the section attaches then warm the slide, (j) When the section is dry, remove the dried film of O.C.T. arrows) with a forceps. Note the two rows of sections toward the slide label down) have the film already removed...

Pyrosequencing has been successfully performed on DNA from cell lines, blood, serum, plasma, paraffin-embedded tissue frozen tissue, and whole genome-amplified product. In addition, complementary DNA from various sources has also been successfully pyrosequenced. 

Larger specimens can be handled in two ways, depending on the thickness of the tissue. Frozen sections can be stained or, alternatively, very small tissue pieces can be stained then embedded in paraffin wax and sectioned. Paraffin embedding is described in section 7.3.1.1 (see Note 7). 

Grind the frozen tissue to a fine powder using a mortar and pestle, keeping the tissue frozen throughout. 

Vegetable Tissue, Frozen, Enzyme Activity in (Joslyn). IX 613... 

Hypothermia—Indirect cryodestruction Metabolic uncoupling Energy deprivation Ionic imbalance Disruption of acid-base balance Waste accumulation Membrane phase transitions Cytoskeletal disassembly Frozen State—Direct cryodestruction Water solidification Hyperosmolality Cell-volume disruption Protein denaturation Tissue shearing Intracellular-ice propagation Membrane disruption Microvascular Thawed State Direct effects... 

Table IV records a study of tissues in which the nitrosating agent occurred. Two mice were exposed to NO j killed with C02> and dissected to give the skin, liver, lungs, and remainder of the body ("carcass") Corresponding tissues of the 2 mice were combined and frozen in liquid N The entire tissue, or 5 g of the carcasses (total weight, 41 g) was homogenized, 10 mg...

Flavonoids may be extracted from fresh or frozen plant tissues or from herbarium material, although freeze-dried material may also be utilized [34]. It is very important to ensure that the matoial to be extracted is finely divided, whether by cutting or emshing, to ensure proper extraction. Extraction can be carried out successively with methanol containing some 10% of wate and thm with a 1 1 mixture of methanol and water. Each extraction should be carried out for a period of about 2 h, shaking or stirring to facilitate the process. The extracts are then combined for chromatographic separation. 

Stability Assessment In general there is no formal stability study prior to the certification of a natural matrix S RM. H owever, the stability of the certified analytes is monitored on a regular basis, typically every 1-3 years depending on the analytes, as the SRMs are analyzed as control samples during the analyses of similar matrix samples. A recent study of PAHs in frozen mussel tissue over nearly 10 years found no significant changes in the concentrations of the measured PAHs (Schantz et al. 2000). 

Schantz MM, Demiralp R, Greenberg RR, Hays MJ, Parris, RM, Porter BJ, Poster DL, Sander LC, Schiller SB, Sharpless KS, and Wise SA (1997a) Certification of a frozen mussel tissue standard reference material (SRM 1974a) for trace organic constituents. Fresenius J Anal Chem 358 431-440. 

ScHANTZ MM, Porter BJ, and Wise SA (2000) The stability of polycyclic aromatic hydrocarbons in frozen mussel tissue. Polycyclic Aromat Compd (in press). 

Wise SA, Benner BA Jr, Christensen RG, Roster BJ, Kurz J, Schantz MM, and Zeisler R (1991) Preparation and analysis of a frozen mussel tissue reference material for the determination of trace organic constituents. Environ Sci Tech 25 1695-1704. 

OPPTS 860.1500, p. 16, indicates that 3-5 sampling points should be included in the decline trials. For applications close to the normal harvest time, the RAC may be harvested at selected intervals between the time of final application and a normal harvest or slightly delayed harvest. If the application is made long before the normal harvest, then representative plant tissues (including immature RAC) may need to be harvested in order to stretch the harvest period. A single composite sample is all that is required from each selected time point, but two or more samples may be harvested to reduce uncertainty about the actual amount of residue present at each sample time interval. These decline samples should be collected and treated the same as normal RAC samples. The samples should be frozen as soon as possible after collection. The instructions for decline sample collection and handling described in the protocol should be followed closely. 

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