As was first published by Palacios in 2000, not only is agarose cheap and effective for use in laboratories, but it can be recycled. Not many labs do this but there’s no good reason not to. It’s possible to buy 200 grams for about $100 but why spend any money at all when recycling it is so easy?
The most important aspect of recycling agarose is to keep it moist. When agarose dries out it becomes hard and while you can remelt it, the percentage of agarose in solvent changes.
Over time, molecules disperse through agarose. If you decide to begin recycling agarose in your lab, the setup is very easy.
- Take old gels and immerse them in a beaker of water. Let them sit for a few days, or even a week.
- After some multiple-day duration has passed, transfer the gels to a new beaker of water.
- Repeat this step a third time.
- Now you can either do as the referenced paper suggests and dry the agarose to later grind into a powder again, or you can simply remove the gel from the water, break it apart, and put the pieces in a jar, which should be kept in a warm water bath (about 55 or 60 degrees), sealed with a lid.
When you need to pour a new gel, take one of the gel pieces sitting in the warm water bath and microwave it to melt it down, then pour it into the same mold you originally used and treat it like new.
Depending on how you use ethidium bromide, it might be necessary to add more over time as it is removed when gels are run (albeit slowly) and it’s also removed during the rinse stages of the gels.
Also keep in mind ethidium bromide is hazardous and if you’re going to do rinse stages, it’s a good idea to get some ethidium bromide teabags to absorb the dangerous chemical. Just leave these teabags in the discarded rinse water to absorb ethidium bromide before pouring it down the drain.
For more information on disposing of ethidium bromide properly, visit this site on Ethidium Bromide Disposal.
