Specimen: Blood . Amount needed is 2ml for a child and 10 ml for an adult to give 1:10 dilution of the specimen.
Culture: Blood culture . Blood culture bottle should have 18 ml and 90 ml of broth for a child and an adult respectively. NB: Numbers of culture required are 3-6 with in 24 hrs. Time of incubation of blood culture is 7 days and subculture is done in first, third and seventh day of incubation. If the appearance of blood culture is changed to cloudy, it indicates bacterial growth.
Interpretation of results
Positive bacterial growth in three of blood culture broth -----
Positive bacterial growth in two of blood culture Probable diagnosis
Positive bacterial growth in one of blood culture Contamination
Common contaminants of blood culture S. epidermidis Corynebacterium spp. Bacillus spp.