BACKGROUND AND PURPOSE: Rapid identification of microbes in the bloodstream is 
crucial in managing septicemia because of its high disease severity, and direct 
identification from positive blood culture bottles through matrix-assisted laser 
desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) can 
shorten the turnaround time. Therefore, we developed a simple method for rapid 
microbiological identification from positive blood cultures by using MALDI-TOF 
MS.
METHODS: We modified previously developed methods to propose a faster, simpler 
and more economical method, which includes centrifugation and hemolysis. 
Specifically, our method comprises two-stage centrifugation with gravitational 
acceleration (g) at 600g and 3000g, followed by the addition of a lysis buffer 
and another 3000g centrifugation.
RESULTS: In total, 324 monomicrobial bacterial cultures were identified. The 
success rate of species identification was 81.8%, which is comparable with other 
complex methods. The identification success rate was the highest for 
Gram-negative aerobes (85%), followed by Gram-positive aerobes (78.2%) and 
anaerobes (67%). The proposed method requires less than 10 min, costs less than 
US$0.2 per usage, and facilitates batch processing.
CONCLUSION: We conclude that this method is feasible for clinical use in 
microbiology laboratories, and can serve as a reference for treatments or 
further complementary diagnostic testing.