The distribution of ribonucleoprotein (RNP) within the mitotic spindle of newt lung epithelial cells was studied with the high voltage electron microscope (HVEM) using Bernhard's uranyl-EDTA-lead staining of thick sections in conjunction with the ribonuclease digestion of fixed cells. The results indicate that aside from ribosomes, the major RNP-containing components of the spindle are the kine...

The ecotoxicological and chemical response of five metals (Cd, Cr, Cu, Ni, and Zn) to selective fractionation techniques was assessed using the organism Daphnia magna. The metals Cu and Zn revealed similar toxicity patterns, showing an increased toxicity when lowering the pH, a marked reduction in toxicity after addition of ethylenediaminetetraacetic acid (EDTA). Similar toxicity reductions wer...

A pre-lysis buffer washing procedure was introduced to DNA extraction from a forest soil with high organic matter and iron oxide contents. Sodium phosphate of 0.1 M (pH 7.5) was used as a buffer to wash soil samples when subsequent lysis buffer was phosphate, and 20 mM EDTA (pH 7.5) was used when subsequent lysis buffer included EDTA. Initial experiments were not successful because the DNA extr...

1. We have isolated a mutant of Escherichia coli K12 (strain AN295) that forms de-repressed amounts of Mg(2+),Ca(2+)-stimulated adenosine triphosphatase. 2. The Mg(2+),Ca(2+)-stimulated triphosphatase activity was separated from membrane preparations from strain AN295 by extraction with 5mm-Tris-HCl buffer containing EDTA and dithiothreitol, resulting in a loss of the ATP-dependent transhydroge...

Hepatozoon (H.) americanum and H. canis are the etiological agents of canine hepatozoonosis, a disease that is found worldwide and is also prevalent in the southeastern United States. Current laboratory diagnosis of canine hepatozoonosis caused by H. americanum is usually dependent on visual identification of Hepatozoon "onion skin cysts" in muscle biopsies, an approach that requires invasive s...

Using o-pthaldialdehyde (OPT) fluorescence, the amino acids associated with DNA were studied following exposure of intact Chinese hamster ovary cells to chromate. Rigorous extraction with EDTA, acid, or base was required to release the amino acids cross-linked to the DNA isolated from control or chromate-treated cells by standard procedures (i.e., proteinase K, phenol, etc.). Amino acids resist...

introduction a large volume of sediments are dredged from water bodies such as ports, waterways and wetlands and deposited on land. sediments are typically polluted by contaminants such as heavy metals. metals in sediments are in soluble, carbonate bound, fe-mn oxide, sulfide/organic matter bound and residual fractions. the metal solubility and mobility are mainly controlled by organic matter c...

A critical appraisal of single-step extraction procedures of chromium species from soil was done in terms of their selectivity towards Cr(III) and Cr(VI) species. Samples of natural mineral and organic soil and samples of soil enriched with different chromium compounds of various solubility (in liquid or solid form) were used to simulate contamination of soil by liquid and solid wastes. The eff...

The potential bioavailability of Hg from soil might be estimated by a variety of chemical extraction procedures, differing in the extraction agent, its concentration, the sample weight, and the time of extraction. In this study, a comparative analysis of several extraction methods, commonly used for obtaining the mobile and potentially mobilizable phase of the mercury was carried out. Concentra...