Counting Caenorhabditis elegans: Protocol Optimization and Applications for Population Growth and Toxicity Studies in Liquid Medium

Scanlan, Leona D.; Lund, Steven P.; Coşkun, Sanem Hoşbaş; Hanna, Shannon K.; Johnson, Monique E.; Sims, Christopher M.; Brignoni, Karina; Lapasset, Patricia E.; Petersen, Elijah J.; Elliott, John T.; Nelson, Bryant C.

doi:10.1038/s41598-018-19187-3

Cited by 40 publications

(40 citation statements)

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“…Nematode model for toxicity testing is widely practiced within the research laboratories and is universally recognized . C .…”

Section: Resultsmentioning

confidence: 99%

“…Nematode model for toxicity testing is widely practiced within the research laboratories and is universally recognized. 32,33 C. elegans is a free-living nematode that is vulnerable to a diverse spectrum of chemicals. The swirling motion of C. elegans in liquid media assists in assessing the toxicity of lead compounds that are readily soluble in water/M9 buffer.…”

Section: Bio-composites Were Non-toxic To C Elegansmentioning

confidence: 99%

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Biocompatible agar/xanthan gum composite films: Thermal, mechanical, UV, and water barrier properties

Rukmanikrishnan

Rajasekharan

Lee

et al. 2019

Polymers for Advanced Techs

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Binary composite films were prepared from agar (A) and xanthan gum (X) with different weight percentages. The composite films were transparent, lightweight, eco‐friendly, and biodegradable. The structure and morphology of the prepared agar and AX composite films were confirmed by Fourier transform infrared spectroscopy (FT‐IR), X‐ray powder diffraction (XRD), and scanning electron microscopy (SEM) technique. The glass transition temperature (Tg) and melting temperature (Tm) of the AX composite films was slightly improved, when compared with the neat agar. Thermogravimetric analysis (TGA) analysis showed a considerable increment in the char yield and an improved thermal stability. The tensile strength was in the range of 25 to 40 MPa, and elongation at break was in the range of 28.9 to 39.4%. Though, the water vapor permeability (WVP) value reduced in the composite films the difference was not significant. From the mechanical studies, we can deduce that agar and xanthan gum are compatible and miscible with one another leading to prospects of their composite films being considered for different biomedical and packaging applications.

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“…Nematode model for toxicity testing is widely practiced within the research laboratories and is universally recognized . C .…”

Section: Resultsmentioning

confidence: 99%

Section: Bio-composites Were Non-toxic To C Elegansmentioning

confidence: 99%

Biocompatible agar/xanthan gum composite films: Thermal, mechanical, UV, and water barrier properties

Rukmanikrishnan

Rajasekharan

Lee

et al. 2019

Polymers for Advanced Techs

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show abstract

“…Caenorhabditis elegans killing assay. Wild-type N2 C. elegans was purchased from the Caenorhabditis Genetics Center at the University of Minnesota and cultured as described previously (50,51). Synchronized L4 stage to young-adult worms grown on nematode growth medium (NGM) agar plates with Escherichia coli OP50 were washed with sterilized M9 buffer and resuspended in slow-killing (SK) medium.…”

Section: Methodsmentioning

confidence: 99%

Iron/Heme Metabolism-Targeted Gallium(III) Nanoparticles Are Active against Extracellular and Intracellular Pseudomonas aeruginosa and Acinetobacter baumannii

Choi

Britigan

Narayanasamy

2019

Antimicrob Agents Chemother

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Iron/heme acquisition systems are critical for microorganisms to acquire iron from the human host, where iron sources are limited due to the nutritional immune system and insolubility of the ferric form of iron. Prior work has shown that a variety of gallium compounds can interfere with bacterial iron acquisition. This study explored the intra-and extracellular antimicrobial activities of gallium protoporphyrin (GaPP), gallium mesoporphyrin (GaMP), and nanoparticles encapsulating GaPP or GaMP against the Gram-negative pathogens Pseudomonas aeruginosa and Acinetobacter baumannii, including clinical isolates. All P. aeruginosa and A. baumannii isolates were susceptible to GaPP and GaMP, with MICs ranging from 0.5 to ϳ32 g/ml in iron-depleted medium. Significant intra-and extracellular growth inhibition was observed against P. aeruginosa cultured in macrophages at a gallium concentration of 3.3 g/ml (5 M) of all Ga(III) compounds, including nanoparticles. Nanoparticle formulations showed prolonged activity against both P. aeruginosa and A. baumannii in previously infected macrophages. When the macrophages were loaded with the nanoparticles 3 days prior to infection, there was a 5-fold decrease in growth of P. aeruginosa in the presence of single emulsion F127 copolymer nanoparticles encapsulating GaMP (eFGaMP). In addition, all Ga(III) porphyrins and nanoparticles showed significant intracellular and antibiofilm activity against both pathogens, with the nanoparticles exhibiting intracellular activity for 3 days. Ga nanoparticles also increased the survival rate of Caenorhabditis elegans nematodes infected by P. aeruginosa and A. baumannii. Our results demonstrate that Ga nanoparticles have prolonged in vitro and in vivo activities against both P. aeruginosa and A. baumannii, including disruption of their biofilms.

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“…Caenorhabditis elegans is viewed as a universal model in studies on molecular biology, genetics, or in the toxicities of drugs and chemicals 8 , 9 . C .…”

Section: Introductionmentioning

confidence: 99%

“…C . elegans models provide an alternative to the use of rodent models 8 . Also in Frank R. Lautenberg, Chemical Safety for the 21st Century Act, 2016 mandates that the U.S. Environmental Protection Agency explore possibilities of using “non-vertebrate” models for toxicity testing 8 .…”

Section: Introductionmentioning

confidence: 99%

LED based real-time survival bioassays for nematode research

Rajasekharan

Raorane

Lee

2018

Sci Rep

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Nematode bioassays are extensively conducted worldwide, either for screening anthelmintic drugs or for assessing the toxicity of drug candidates. Recently, the US Environmental Protection Agency mandated the use of invertebrate models including nematodes especially Caenorhabditis elegans, for toxicity testing as an alternative to rodent models. The significance of nematode bioassays in the biological sciences is escalating, but no standardized protocol is available to assess nematode mortality in a liquid medium. Manual counting under white light is the only approach currently practiced, which exhibit large variabilities and false positive results. Here, we describe an innovative counting strategy that employs light-emitting diode (LED) technology. We found that the nematodes stopped moving under white light (360–760 nm) when administered with sub-lethal dosage (LC50) of a toxic drug, whereas they responded rapidly to blue (450–490 nm) and ultraviolet (UV) (100–400 nm) LED lights. Furthermore, paralyzed nematodes responded in less than 5 seconds to a LED pulse. The response to the LED stimulus was distinctively noted in C. elegans dauers, which squirmed away from illuminated sites within seconds. LED produced an incoherent beam, and uniformly distributed light across the sampling area. In conclusion, this method is more accurate than the conventional counting techniques, and enables us to differentiate paralyzed and dead nematodes virtually in real-time. Furthermore, this technique would appear to be suitable for incorporating a motion-sensor based automated system.

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Counting Caenorhabditis elegans: Protocol Optimization and Applications for Population Growth and Toxicity Studies in Liquid Medium

Cited by 40 publications

References 40 publications

Biocompatible agar/xanthan gum composite films: Thermal, mechanical, UV, and water barrier properties

Biocompatible agar/xanthan gum composite films: Thermal, mechanical, UV, and water barrier properties

Iron/Heme Metabolism-Targeted Gallium(III) Nanoparticles Are Active against Extracellular and Intracellular Pseudomonas aeruginosa and Acinetobacter baumannii

LED based real-time survival bioassays for nematode research

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