Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Simultaneous Pre-Concentration of Cadmium and Lead in Environmental Water Samples with Dispersive Liquid-Liquid Microextraction and Determination by Inductively Coupled Plasma-Atomic Emission Spectrometry

<strong>The dispersive liquid–liquid microextraction (DLLME) method for determination of Pb⁺² and Cd⁺² ions in the environmental water samples was combined with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Ammonium pyrrolidine dithiocarbamate (APDC), chloroform and ethanol were used as chelating agent, extraction solvent and disperser solvent, respectively. Some effective parameters on the microextraction and the complex formation were selected and optimized. These parameters included extraction and disperser solvent type as well as their volume, extraction time, salt effect, pH, sample volume and amount of the chelating agent.   Under the optimum conditions, the enrichment factor of 75 and 105 for Cd⁺² and Pb⁺² ions respectively was obtained from only 5.00mL of water sample. The detection limit (S/N=3) was 12 and 0.8ngmL⁻¹ for Pb and Cd respectively. The relative standard deviation (RSDs) for five replicate measurements of 0.50 mgL⁻¹ of lead and cadmium was 6.5 and 4.4 % respectively. Mineral, tap, river, sea, dam and spiked water samples were analyzed for Cd and Pb amount.</strong

Determination of Zinc Ions in Environmental Samples by Dispersive Liquid- Liquid Micro Extraction and Atomic Absorption Spectroscopy

<div><p>In this work preconcentration of the Zn ions was investigated in water sample by Dispersive liquid- liquid micro extraction (DLLME) using chloroform as an extraction solvent, methanol as a disperser solvent and 8-Hydroxyquinoline as a chelating agent. The determination of extracted ions was done by graphite furnace atomic absorption spectrometry. The influence of various analytical parameters including pH, extraction and disperser solvent type and volume and concentration of the chelating agent on the extraction efficiency of analyses was investigated. After extraction, the enrichment factor was 26 and the detection limit of the method was 0.0033 µg l^-1 and the relative standard deviations (R.S.D) for five determinations of 1 ng/ml Zn were 7.41%.</p><p> </p></div

Dispersive liquid-liquid microextraction (DLLME) combined with graphite furnace atomic absorption spectrometry (GFAAS) for determination of trace Cu and Zn in water Samples

Dispersive liquid-liquid microextraction (DLLME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for the determination of trace amounts of Copper and Zinc ions using 8-hydroxyquinoline (8-HQ) as chelating agent. Several factors influencing the microextraction efficiency of Cu and Zn and their subsequent determinations, such as pH, extraction and disperser solvent type and their volume, concentration of the chelating agent and extraction time were studied, and the optimized experimental conditions were established. After extraction, the enrichment factors were 25 and 26 for Cu and Zn, respectively. The detection limits of the method were 0.025 and 0.0033 μg/L for Cu and Zn, and the relative standard deviations (R.S.D) for five determinations of 1 ng/ml Cu and Zn were 8.51% and 7.41%, respectively