One of the common tests used in identifying medically-important Gram positive cocci centers on what the bacteria do with red blood cells. Many possess enzymes that destroy erythrocytes, a process called hemolysis. For this reason, it is not uncommon for medically-important Gram positive cocci to be aseptically streaked on blood agar to see the results.
This is done in the Virtual Lab, too. Go to Micro Digital Media Exercise 15 and learn about the forms of hemolysis.
Your instructor will alert you on whether to turn in the Virtual Lab Report and/or MDM exercises for this activity. When done, you may be asked to take a quiz on this material.