1. Microarray Technique, Analysis, and Applications in Dermatology Jennifer Villaseñor-Park 1 and Alex G Ortega-Loayza 2 1 Department of Dermatology, University of Pittsburgh Medical Center; 2 Virginia Commonwealth University

2. Microarray: Introduction Used for –Assessing gene expression levels –Genome-wide studies and genotyping –Evaluating microRNA levels

3. How do microarrays work? Microarray chips are created that contain many thousands of small DNA segments (probes) Probes are arranged in a known and orderly fashion (the array) Sample mRNA or its corresponding cDNA is labeled and exposed to the DNA probe on the chip If a given gene is expressed, the mRNA hybridizes to the DNA segment on the chip and can be detected

4. Microarrays Types of array platforms: –Filter arrays (i.e., macroarrays) Lower probe density compared to spotted or oligonucleotide arrays Lower sensitivity (e.g., low-abundance sequences may be missed) –Spotted glass slide arrays –In situ synthesized oligonucleotide arrays Common probes –Complementary DNA (cDNA) –Oligonucleotides

5. Oligonucleotide arrays Control cells Experimental cells Cy3Cy5 Targets Hybridize targets to probes

6. cDNA arrays Control cells Experimental cells Cy3Cy5 Targets Hybridize targets to probes

7. Applications in dermatology Melanoma Cutaneous T-cell lymphoma Psoriasis Scleroderma Lupus erythematosus Others