LN transplantation to the ear pinna. LNs from 4-week-old donor mice were inserted into subdermal pockets made in the ear pinna of adult C57BL/6 mice. The surgical incision was then sealed with veterinary-grade adhesive. Three to 4 weeks after engraftment, ear pinnae were harvested and sectioned for conventional histologic analysis. (A) Ear pinna before dissection. (B) Ear pinna containing the tLN, black arrows indicate the tLN surrounded by blood vessels. (C) Soft x-ray imaging identifies tLNs in ear pinna of live animals, marked by white arrows. (D) Ear pinna containing the tLN stained with H&E (magnification, ×10).