Methylation (image) Brown University Share Print E-Mail Caption A new technique based on microarrayss distinguishes cell types in blood by looking at signature degrees of methylation in DNA. Yellow represents no methylation, and blue represents full methylation. Credit Kelsey Lab/Brown University Usage Restrictions Use with credit. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.