Epidermal Cell Proliferation by Dansyl Chloride Labeling

The objective of this study is to determine the effect of a test material on epidermal cell proliferation through the use of dansyl chloride. Due to its ability to bind to amino groups, dansyl chloride is used for fluorescent tagging of protein in the stratum corneum. Cell renewal can be evaluated by comparing the rate at which the fluorescence diminishes on untreated and test-product-treated sites tagged with dansyl chloride.

It is recommended that 35 subjects be enrolled in order to complete the study with 30 subjects. The duration of the study is typically 3 weeks of daily (Monday through Friday) observations of the test sites following dansyl chloride application. An additional 2 weeks of product application may precede the dansyl chloride application if a pre-treatment phase is required. The test schedule and duration of the study may be modified to accommodate the specific mechanism of action of the test product.


Qualified subjects, having no dermal abnormalities on the volar surface of the forearms, are given a bar of non-moisturizing soap to be used for all bathing/cleansing of the arms for the duration of the study. Depending on the type of test product, a pre-treatment phase may be recommended. During this phase, the test product is applied daily (or as otherwise instructed) to the volar surface of one randomly assigned forearm. Following the pre-treatment phase, a dansyl chloride suspension is applied to a 3.5 cm X 3.5 cm area on two adhesive patches and one patch is applied to each forearm. The patches are removed after 24 hours and the sites are graded for intensity of fluorescence. The test product is applied daily, or as otherwise instructed, to the designated forearm and subjects return for daily monitoring (Monday through Friday) of the intensity of fluorescence on the untreated and treated test sites. Observations and grading are performed in a darkened room using a Wood’s Lamp by a trained technician blinded to treatment assignment.

Individual units of the test product must be provided by you, the Sponsor, in a quantity sufficient to last each subject for the number of required applications. Eurofins CRL staff will label each unit with identifying study and subject numbers prior to distribution.

Interpretation & Reporting of Results

The diminishing of fluorescent staining indicates cell proliferation. Appropriate statistical analyses will be applied to determine if a statistically significant difference in the rate of cell turnover exists, comparing the treated to the untreated site.

Scheduling a Safety-In-Use study

To schedule, please contact your Client Services representative at 732-981-1616 or contact us by e-mail: infonj@cpt.eurofinsus.com.