This study is designed to evaluate background fluorescence of participants of different ages, gender, and skin color. In addition, 48-hour tolerability of the sensor and adhesive will be evaluated.

The MediBeacon Transdermal GFR Measurement System investigational is intended to measure the Glomerular Filtration Rate (GFR) in patients with normal or impaired renal function by noninvasively monitoring fluorescent light emission from an exogenous tracer agent (MB-102) over time. The device utilized in this study is the Brilliance device. Approximately 1 male and 1 female from each age cohort (18-50 years; 51+ years) and clustered Fitzpatrick Skin Scale groups (I-II [Light, pale white; white, fair]; III-IV [Medium, white to olive; olive, moderate brown]; and V-VI [Brown, dark brown; black, very dark brown to black]) will be recruited, for a total of 12 participants. Participants will have Brilliance device sensors placed on two locations on their skin, which will remain for 48 hours. The sensor location will be prepared through shaving and cleaning (as applicable), placed on the skin via standard single-use adhesive pads, and baseline measurements collected. Participants may undergo activities of daily living while measurements are being collected. Light pressure and other minor perturbations may be applied to the sensors to evaluate the effect on background fluorescence. Adverse events associated with sensor placement (such as skin irritations) will be recorded.

Inclusion Criteria:

• Healthy male and female adults age 18 and older
• 2 age cohorts to be recruited: 18 - 50 years of age and 51+ years or older
• Skin color groups to be recruited in accordance with the Fitzpatrick Skin Scale (I - VI)
• Participants willing to sign the Institutional Review Board (IRB) approved informed consent form prior to the initiation of any study specific procedures.

Exclusion Criteria:

• History of skin sensitivity to adhesives (e.g. Band-Aids, surgical tape)
• Any characteristics which, in the opinion of the investigator, makes the participant a poor candidate for participation in the clinical trial
• Significant scarring, tattoos or alterations in pigmentation on the standardized sensor locations that would alter sensor readings versus other areas of the skin