In this article we present a general protocol for measuring life span of nematodes maintained on solid media with UV-killed bacterial food.
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Method Article
Measuring Caenorhabditis elegans Life Span on Solid Media
In This Article
Summary
Abstract
Aging is a degenerative process characterized by a progressive deterioration of cellular components and organelles resulting in mortality. The nematode Caenorhabditis elegans has emerged as a principal model used to study the biology of aging. Because virtually every biological subsystem undergoes functional decline with increasing age, life span is the primary endpoint of interest when considering total rate of aging. In nematodes, life span is typically defined as the number of days an animal remains responsive to external stimuli. Nematodes can be propagated either in liquid media or on solid media in plates, and techniques have been developed for measuring life span under both conditions. Here we present a generalized protocol for measuring life span of nematodes maintained on solid nematode growth media and fed a diet of UV-killed bacteria. These procedures can easily be adapted to assay life span under various common conditions, including a diet consisting of live bacteria, dietary restriction, and RNA interference.
Protocol
Part 1: Prepare nematode growth media (NGM) plates
This section describes the preparation of the solid NGM plates for use in the life span experiment. A basic life span experiment requires two types of plates: standard NGM plates, which contain no additives, and Amp/FUDR plates, which have both ampicillin (Amp) and fluorodeoxyuridine (FUDR) added to the NGM. Ampicillin is used to prevent foreign bacterial contamination. FUDR inhibits cell division, reduces egg production, and prevents eggs from hatching. The use of FUDR for longevity analysis does not affect adult life span and removes the need to transfer worms every few days in order to sep....
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Discussion
The genetic control of longevity has been studied extensively in C. elegans, largely due to the ease and rapidity with which life span can be determined. The protocol discussed in this article describes a basic framework for obtaining reproducible life span data in C. elegans and can also be applied to relatednematode species.2 By making some simple alterations these procedures can be adapted to measure life span under a variety of conditions. Here we will discuss several common variations, i.......
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Acknowledgements
This work was supported by a Glenn/AFAR Breakthroughs in Gerontology Award and NIH Grant 1R01AG031108-01 to M. K. G. S. is supported by NIH training grant P30AG013280. M. K. is an Ellison Medical Foundation New Scholar in Aging.
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Materials
| Name | Company | Catalog Number | Comments | |
|---|---|---|---|---|
| Agar | Reagent | Fisher Scientific | DF0145-17-0 (214530) | |
| Ampicillin | Reagent | MidSci | 0339 | |
| BactoTryptone | Reagent | Fisher Scientific | DF0123-17-3 (211705) | |
| BactoPeptone | Reagent | Fisher Scientific | DF0118-17-0 (211677) | |
| CaCl2 | Reagent | Fisher Scientific | NC9699248 (1332-01) | |
| Carbenicillin | Reagent | Gold Biotechnology | C0109 | |
| Cholesterol | Reagent | Sigma-Aldrich | C75209 | |
| Fluorodeoxyuridine (FUDR) | Reagent | Sigma-Aldrich | F0503 | |
| Isopropyl β-d-Thiogalactopyranoside (IPTG) | Reagent | Gold Biotechnology | I2481C5 | |
| KPi Dibasic | Reagent | Fisher Scientific | 5087862 (3252-01) | |
| KPi Monobasic | Reagent | Fisher Scientific | 5087861 (3246-01) | |
| MgSO4 | Reagent | Fisher Scientific | NC9561800 (2500-01) | |
| NaCl | Reagent | Fisher Scientific | S251 | |
| Tris | Reagent | Sigma-Aldrich | T1503 | |
| Yeast Extract | Reagent | Fisher Scientific | DF0886-17-0 (288620) |
References
- Wood, W. B. The Nematode Caenorhabditis elegans. Wood, W. B. , Cold Spring Harbor Laboratory Press. Cold Spring Harbor, NY. 1-16 (1988).
- Sutphin, G. L., Kaeberlein, M. Dietary restriction by bacterial deprivation increases life span in wild-derived nematodes. Exp Gerontol. 43, 130-135 (2008).....
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