Update: We had the best results using 90% isopropyl alcohol, Dawn detergent, and iodized salt. BTW, I keep my DNA supplies in a kit. The meat tenderizer is supposed to be good for a year. I’ll check next year when I teach Bio again.
Today, the Bio class is extracting DNA. Here are instructions to extract DNA from just about anything. The key is to use fresh meat tenderizer. We use split peas. Additionally, this lab is more inquiry-based. I have two types of dish soap and different percentages of alcohol. When I have a large group I add ionized salt vs sea salt, rubbing alcohol vs ethyl alcohol, and chilled vs room-temperature alcohol. The kids can form a hypothesis. For example, one group might hypothesize that sea salt will produce more DNA than iodized salt or chilled ethanol may produce more DNA than room-temperature ethanol. My kids are using this lab for their third, formal lab report since they need to write at least four for several online schools to receive lab credit. This lab might take two class periods to complete because kids need to perform two tests for each trial. The white threads on top of the pea solution are DNA.
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