Wrapping culture plates with Parafilm M® increases Caenorhabditis elegans growth

Abstract

ObjectiveParafilm M® is a moisture-resistant thermoplastic commonly used to seal Nematode Growth Media (NGM) agar plates on which the nematode Caenorhabditis elegans is cultured. This practice reduces media dehydration and microbial contamination. However, the effects on C. elegans individuals of placing this barrier between the external environment and the interior of the NGM plate are currently unknown. Our research aims to determine if this common practice engenders developmental changes, such as growth, that could subsequently and unintentionally alter experimental data. We compared the larval growth over 48 h of animals cultured on Parafilm-wrapped and unwrapped control NGM plates.ResultsWrapping culture plates with Parafilm significantly accelerated and increased larval growth, with a 0.87 μm/h increase in growth rate (~ 6%) and a 37.90 μm increase in the change in growth (Δgrowth; ~ 5%) over 48 h. Therefore, C. elegans investigators should be aware that wrapping their experimental cultures with Parafilm may result in statistically detectable changes in worm growth and possibly other developmental processes.

Sarracenia purpurea glycerol‐3‐phosphate acyltransferase 5 confers plant tolerance to high humidity in Arabidopsis thaliana

“…Moisture‐resistant parafilm and porous micropore tape are usually used to seal plant growth medium plates. Compared to micropore tape, parafilm has the limited gas exchange from the plate and outside atmosphere and an increase of ambient air humidity in the plate (Banerjee et al, 2019; Shinn‐Thomas et al, 2019; Xu et al, 2019). The wild type and Atgpat5‐1 were grown on 1/2 MS medium sealed with parafilm or micropore tape for 7 days.…”

Phenotypic Screening in C. elegans as a Tool for the Discovery of New Geroprotective Drugs

“…C. elegans is exquisitely sensitive to a wide range of environmental factors such as temperature [ 213 ], humidity [ 214 ], light exposure [ 215 ] and population density [ 216 ]. In fact, it has been demonstrated that the growth rate of C. elegans larvae was significantly accelerated by simply wrapping the Petri plates, in which they are cultured, with Parafilm M ® [ 217 ]. It is also worth noting that the effect of interventions can be temperature dependent.…”