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Remote Ready Biology Learning Activities has 50 remote-ready activities, which work for either your classroom or remote teaching.
Cheap fake blood
If you have insufficient budget for the recommended kits, you can make the fake blood samples and anti-sera by adapting the instructions to use food coloring, milk, vinegar and water provided on pages 1-3 of "Teachers’ Talking Science – Blood Typing", available at http://www.talkingscience.org/wp-content/uploads/2011/03/tts-bloodtyping.pdf . However, you should be aware that this cheaper alternative is significantly more complicated for you and your students to use; specifically, you will have to designate different antisera for each sample in order to get the desired results.