Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Cells of the Epidermis

Cells of the Epidermis

The epidermis is made of four or five layers of epithelial cells, depending on its location in the body. From deep to superficial, these layers are the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
The cells in all these layers except the stratum basale are called keratinocytes, a type of cell that manufactures and stores the protein keratin. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from...

Layers of the Epidermis

Layers of the Epidermis

The epidermis, the outermost layer of the skin, is composed of several distinct layers. From deep to superficial, the layers of the epidermis are as follows:
Stratum Basale
Stratum basale, also known as the stratum germinativum, is the deepest layer of the epidermis. It is composed of a single layer of actively dividing cells called basal cells or basal keratinocytes. These cells constantly undergo cell division to replenish the upper layers of the epidermis. Additionally, melanocytes, which...

Role of Skin in Vitamin D Synthesis

Role of Skin in Vitamin D Synthesis

The skin plays a crucial role in the synthesis of vitamin D, a vital nutrient for various physiological processes in the body. Vitamin D is unique because it can be synthesized in the skin through a series of chemical reactions triggered by exposure to ultraviolet B (UVB) radiation from sunlight.
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).

Pigmentation

Pigmentation

The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis.

Nature communications·2016

Same author

Randomized trial of a dual-hormone artificial pancreas with dosing adjustment during exercise compared with no adjustment and sensor-augmented pump therapy.

Diabetes, obesity & metabolism·2016

Same author

Elastotic degenerative change and yellowish discolouration in photoaged skin.

Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging (ISSI)·2016

Same author

The advantages of creating a positive radiation safety culture in the higher education and research sectors.

Journal of radiological protection : official journal of the Society for Radiological Protection·2015

Same author

Home phototherapy for psoriasis: a review and update.

Clinical and experimental dermatology·2015

Same author

Erythema action spectrum of topical 8-methoxypsoralen-sensitized skin re-evaluated: implications for routine clinical practice.

The British journal of dermatology·2015

Search research articles

Related Experiment Video

Updated: Jun 24, 2026

Measuring and Modeling Contractile Drying in Human Stratum Corneum

Measuring and Modeling Contractile Drying in Human Stratum Corneum

Published on: March 1, 2017

Human stratum corneum as a substrate for in vitro sunscreen testing.

A D Pearse¹, C Edwards

¹Cutest Systems Ltd, 178 Whitchurch Road, Cardiff, CF4 3NB, UK and Department of Dermatology, University of Wales College of Medicine, Heath Park, Cardiff, CF4 4XN, UK.

International Journal of Cosmetic Science

|March 14, 2009

Summary

This study developed an inexpensive, portable instrument for sunscreen evaluation. Human stratum corneum provides more accurate SPF predictions than Transpore™ tape, especially for high SPF products.

More Related Videos

Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale

Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale

Published on: May 28, 2021

Establishing a High Throughput Epidermal Spheroid Culture System to Model Keratinocyte Stem Cell Plasticity

Establishing a High Throughput Epidermal Spheroid Culture System to Model Keratinocyte Stem Cell Plasticity

Published on: January 30, 2021

Related Experiment Videos

Last Updated: Jun 24, 2026

Measuring and Modeling Contractile Drying in Human Stratum Corneum

Measuring and Modeling Contractile Drying in Human Stratum Corneum

Published on: March 1, 2017

Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale

Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale

Published on: May 28, 2021

Establishing a High Throughput Epidermal Spheroid Culture System to Model Keratinocyte Stem Cell Plasticity

Establishing a High Throughput Epidermal Spheroid Culture System to Model Keratinocyte Stem Cell Plasticity

Published on: January 30, 2021

Area of Science:

Dermatology
Photoprotection
Materials Science

Background:

Sunscreen efficacy is crucial for skin cancer prevention.
In vitro methods for Sun Protection Factor (SPF) testing are needed for cost-effectiveness and reproducibility.
Existing in vitro methods may not accurately mimic in vivo skin conditions.

Purpose of the Study:

To construct and validate a portable, inexpensive instrument for evaluating sunscreen efficacy across the UVA and UVB spectrum.
To compare the performance of human stratum corneum versus Transpore™ tape as substrates for in vitro SPF testing.
To assess the correlation of in vitro SPF predictions with in vivo or expected results.

Main Methods:

Developed a dedicated, portable instrument for UVR transmission measurements (290-400 nm).
Utilized both Transpore™ tape and human stratum corneum as substrates for sunscreen application.
Compared predicted SPF values from both substrates against known sunscreen performance.

Main Results:

Human stratum corneum showed greater UVR transmission than Transpore™ tape.
Both substrates correlated well with in vivo SPF, but Transpore™ tape consistently overestimated SPF for products > SPF 20.
Transpore™ tape was unsuitable for alcohol-based sunscreen formulations.

Conclusions:

Human stratum corneum more accurately reflects in vivo skin conditions for sunscreen absorption and spreading compared to Transpore™ tape.
The developed instrument and human stratum corneum substrate offer a promising approach for reliable in vitro sunscreen evaluation.
Accurate SPF testing is vital for effective photoprotection and consumer safety.