Hi worm expert.
I am doing lifespan assay using k-medium in 96-well plate, I want to add 2% glucose, How can I add it .
Is it ok if I exposure the op50 to high glucose NGM or should I add it directly to the K-medium?
If you have other ideas please help
Thanks in advance
Hello, I have used 2% glucose for C. elegans experiments many times in NGM agar, and you are right to be concerned about the OP50 exposure. Even at room temperature the OP50 will consume the glucose and grow disproportionately than a 0% control. So, to stop bacterial metabolism we have used mostly heat inactivated OP50, placing the OP50 culture into a water bath at 65C for 30 minutes is sufficient to inactivate it. We have also used UV irradiation on seeded plates, using a UV Stratalinker at max power for 4 minutes to inactivate it. After that make sure to test viability by streaking the bacteria on a LB plate for growth overnight at 37C, if there is no growth then the inactivation was successful.
There are some caveats about using inactivated OP50 though. C. elegans tend to live a longer lifespan on the dead OP50, however they appear much closer to a nutrient deprivation model, they lay a much smaller brood (which is often developmentally arrested), and they do not prefer the food as much as live OP50.
Hope this helps!