A method for preparing a biological sample for evaluation by Matrix-Assisted Laser Desorption Ionization Time of Flight mass spectrometry the method comprising: obtaining a biological sample; diluting the sample; measuring a turbidity of the diluted sample by nephelometry; a) if the measured sample turbidity is between 2 and 6 McFarland, applying 3 μl of the sample to a surface adapted to deliver the applied sample to a device configured to perform mass spectrometry, drying the applied sample; b) if the measured sample turbidity is higher than 6 McFarland, applying 1 μl of the sample to the surface, drying the applied sample; c) if the measured sample turbidity is in the range of 1 to 2 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample; d) if the measured sample turbidity is in the range of 0.5 to 1 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a third time, 3 μl of the sample over the dried sample, drying the sample; e) if the measured sample turbidity is in the range of 0.25 to 0.5 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a third time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a fourth time, 3 μl of the sample over the dried sample, drying the applied sample; after one of a)-e), applying a matrix over the dried sample, the matrix being adapted for use in the mass spectrometer; and performing mass spectrometry on the sample. obtaining a biological sample; diluting the sample; measuring a turbidity of the diluted sample by nephelometry; a) if the measured sample turbidity is between 2 and 6 McFarland, applying 3 μl of the sample to a surface adapted to deliver the applied sample to a device configured to perform mass spectrometry, drying the applied sample; b) if the measured sample turbidity is higher than 6 McFarland, applying 1 μl of the sample to the surface, drying the applied sample; c) if the measured sample turbidity is in the range of 1 to 2 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample; d) if the measured sample turbidity is in the range of 0.5 to 1 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a third time, 3 μl of the sample over the dried sample, drying the sample; e) if the measured sample turbidity is in the range of 0.25 to 0.5 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a third time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a fourth time, 3 μl of the sample over the dried sample, drying the applied sample; a) if the measured sample turbidity is between 2 and 6 McFarland, applying 3 μl of the sample to a surface adapted to deliver the applied sample to a device configured to perform mass spectrometry, drying the applied sample; b) if the measured sample turbidity is higher than 6 McFarland, applying 1 μl of the sample to the surface, drying the applied sample; c) if the measured sample turbidity is in the range of 1 to 2 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample; d) if the measured sample turbidity is in the range of 0.5 to 1 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a third time, 3 μl of the sample over the dried sample, drying the sample; e) if the measured sample turbidity is in the range of 0.25 to 0.5 McFarland, applying 3 μl of the sample to the surface, drying the applied sample, applying, for a second time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a third time, 3 μl of the sample over the dried sample, drying the applied sample, applying, for a fourth time, 3 μl of the sample over the dried sample, drying the applied sample; after one of a)-e), applying a matrix over the dried sample, the matrix being adapted for use in the mass spectrometer; and performing mass spectrometry on the sample.