GAS-M1 Macrophages, UC San Diego School of Medicine (image) University of California - San Diego Share Print E-Mail Caption This is an electronic microscopy image of Group A Streptococcus (faint purple chains) overlaid with a confocal microscopy image of M protein (red) internalized in macrophages (blue). Credit UC San Diego Health Usage Restrictions Use photo credit as indicated. 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.