zept991

Most of what makes research valuable is not the field/subfield specific nature- it’s learning how to take a project through a longer time period to see ups and downs. That’s usually more about depth (sticking with one area) than breadth. 
You can pick up new techniques pretty fast in a new lab in grad school, most profs don’t care as much about the specific skills (one assay or a type of instrument) as they do a long period of in depth work in a research environment. 

Any research experience is good experience, and you have more than many students coming into grad school. I think your current experiences make you a good candidate for graduate school. However, if you're interested in those other areas, it doesn't hurt to try and get into labs studying those things. If you decide to stay in the lab you're in now, though, you can just state your interest and try and attend relevant seminars on the areas you're interested in.