Can I do a meta-analysis comparing in vitro studies that measure the zone of inhibition around bacteria?

Hi for my final year project I want to do a meta-analysis. All the tutorials/guides I have found online are related to clinical studies with a population. However, my question is whether essential oils can be used to treat bacteria. But I have in vitro studies only which involves growing the bacteria on petri dishes and adding essential oils to them and measuring the zone of inhibition. Furthermore, some studies use more than one essential oil which I want to include on the forest plot individually (if that's possible). Some studies include a control, some do not, the control for those studies that so uses DMSO without essential oil on the bacteria resulting in a zone of inhibition of 0 which does give much to work from when I have to compare the mean of the treatment group and control group.
PLEASE PLEASE PLEASE anyone who is familiar with meta-analysis please get in touch, or if you have an idea on what other statistical analysis I can do for my project.

Thanks in advance! Honestly any help will be much appreciated.


Less is more. Stay pure. Stay poor.
If there is too much variability in study designs, you likely can only write a review of the literature. You cant force some things. if you had say 6-8 studies that were similar you perhaps could pull something off, but that is given comparable designs and treatment strategies.