Yes, I went through a biology PhD program. It was very tasking, I was shooting for finishing in 4 years...ended up finishing in 5 and a half years. My wife was working 3rd shift during that time. So, she was usually asleep when I was at work. We only had maybe an hour together in the morning and 3-4 hours together in the evening until I finished defending my dissertation. Being together was really a help at times and worked against us at times. She wanted to spend more time together but I couldn't. I'm sure that will be the same between the two of you as well. Try to set aside time in between experiments to be together - even if you're just reading papers together. Be open and honest about what time you do or do not have in the week and plan ahead. Good luck!