|  | 
            
                | 
                                
                                        | 
                                                Blood - SEM
                                         |  
                                        | 
                                                This scanning electron micrograph (SEM) depicted a number of red blood cells found enmeshed in a fibrinous matrix on the luminal surface of an indwelling vascular. Magnified 2849x. In this instance, the indwelling catheter was a tube that was left in place creating a patent portal directly into a blood vessel. Some of the erythrocytes are grouped in stacks known as a "Rouleaux formation". 
 Image courtesy of CDC/ Janice Carr.
 |  |