Some bright people have come up with a microneedle patch that will be able to test the fluid between cells for the presence or absence of different antibodies or other biomarkers. It can replace a traditional blood draw and the needles are too short to hit the sensory nerves, making it a practically pain-free experience with many potential applications.
https://medicalxpress.com/news/2021-01-pain-free-microneedle-patch-antibodies-fluid.html