A simplified design for the C. elegans lifespan machine

Abstract

Caenorhabditis elegans ( C. elegans ) lifespan assays constitute a broadly used approach for investigating the fundamental biology of longevity. Traditional C. elegans lifespan assays require labor-intensive microscopic monitoring of individual animals to evaluate life/death over a period of weeks, making large-scale high throughput studies impractical. The lifespan machine developed by Stroustrup et al . (2013) adapted flatbed scanner technologies to contribute a major technical advance in the efficiency of C. elegans survival assays. Introducing a platform in which large portions of a lifespan assay are automated enabled longevity studies of a scope not possible with previous exclusively manual assays and facilitated novel discovery. Still, as initially described, constructing and operating scanner-based lifespan machines requires considerable effort and expertise. Here we report on design modifications that simplify construction, decrease cost, eliminate certain mechanical failures, and decrease assay workload requirements. The modifications we document should make the lifespan machine more accessible to interested laboratories.

The coupling between healthspan and lifespan in Caenorhabditis depends on complex interactions between compound intervention and genetic background

“…To measure the impact of each compound on organismal tolerance of heat stress, we implemented the following augmented Lifespan Machine (LM) protocol [ 38 , 71 ]: 70 animals each placed on 50 mm tight-lidded petri plates with modified NGM and E. coli OP50-1 at 32°C humidity for a duration of four days. For each of two biological replicates (independent trials), we created two technical replicates (single plate) per strain and condition (age and compound or control) per lab.…”

The coupling between healthspan and lifespan in Caenorhabditis depends on complex interactions between compound intervention and genetic background

“…To measure the impact of each compound on organismal tolerance of heat stress, we implemented the following augmented Lifespan Machine (LM) protocol 37,67 : 70 animals each placed on 50 mm tight-lidded petri plates with modified NGM and E. coli OP50-1 at 32 °C humidity for a duration of four days. For each of two biological replicates, we created two technical replicates per strain and condition (age and compound or control) per lab.…”

“…To measure the impact of each compound on organismal resilience to exogenous oxidative stress, we implemented the following LM protocol 37,67 : 70 animals were placed onto each 50 mm tight-lidded petri plate with modified NGM containing 40 mM paraquat (or methyl viologen dichloride, from Sigma-Aldrich), 51 µM FUdR, and E. coli OP50-1. The duration of the paraquat-exposure assays was dependent on the starting age of the animals due to the increased rate of mortality with age.…”

Antioxidants green tea extract and nordihydroguaiaretic acid confer species and strain specific lifespan and health effects in Caenorhabditis nematodes

“…ALM assays were performed as previously described 5,32,34 , based on modification of the protocols published for the Lifespan Machine 31 . Briefly, worms were age synchronized and transferred to intervention plates as described above.…”

“…For NDGA treatment, four of the six C. briggsae and C. tropicalis strains exhibited positive lifespan results on the ALM. Difference in outcome might be the consequence of increased light exposure on the ALMs 32 , as light is known to induce photooxidative stress 33 . ALM protocols also involve fewer potentially damaging animal transfers, and feature no exposure to freshly treated compound plates in mid-to late-life, in contrast to manual assays 34,35 .…”