Exercise 5-25 Micro Lab: Blood Agar
exotoxins produced by several species of gram positive cocci which are able to destroy red blood cells and hemoglobin - usually Streptococcus bacteria
Blood agar contains what?
5% sheep blood in a tryptic soy agar base
three major types of hemolysis
the complete destruction of RBCs and hemoglobin, results in a clearing of the medium around the colonies
the partial destruction of RBCs and produces a greenish discoloration of the agar around the colonies
is non-hemoylsis and appears as simple growth with no change to the medium
hemolysins produced by streptococci
streptolysins come in what two forms?
O and S
is oxygen-labile and expresses maximal activity under anaerobic conditions
is oxygen stable but expresses itself optimally under anaerobic conditions as well
Blood agar is streaked for isolation and then stabbed with a loop. The stabs encourage streptolysin activity because of the reduced oxygen concentration of the subsurface environment. The easiest method.