MICROBIAL IDENTIFICATION TEST USING MALDI-TOF MS METHODOLOGY

Published on : 15 August 2018
Location : Abu Dhabi

We are pleased to announce the addition of the Microbial Identification Test by MALDI-TOF MS to the menu of NRL's Microbiology Laboratory at ICAD, Abu Dhabi. The MALDI-TOF MS (matrix assisted laser desorption ionization-time of flight mass spectrometry) technology represents a revolution in routine pathogen identification as it significantly reduces the turnaround time of bacterial identification by at least 12-24 hours. This is achieved by replacing selected steps from the conventional microbial identification process, such as confirming the genotype samples for isolated cultures. As a result of its accuracy and speed, the test helps improve patient outcomes and quality of care by speeding diagnosis.

Please see more information below.

Order Code

Order Code Name

CPT Code

Specimen type

Volume

Specimen Container

Storage

Specimen Stability

TAT * days

Methodology

183402

Organism ID by MALDITOF

Contact Technical Support

Pure culture isolate of bacteria, 18-72 hours old from an actively growing culture

 

Maintain a subculture at the submitting laboratory.

Pure culture (visible colonies should be present); one bacterial culture transport swab with media

inoculated with the isolate from a pure culture

Sealed agar plate or slant; bacterial swab transport with media

Room temperature

72 hours

For viable isolates: 2 hours

 

For bacterial swab transport: 1 day

 

MALDI-TOF (Matrix Assisted Laser Desorption Ionization – Time of Flight) Mass Spectrometry

Testing Frequency: Daily 

MALDI-TOF MS methodology

The MALDI-TOF MS method uses a laser to ionize the sample consisting of proteins and polymers, where the analyte is embedded in a crystal aromatic matrix. The presence of the matrix causes the large molecules to ionize, instead of decompose or fragment, when absorbing the laser energy. As a result, the analyte ionizes into a gas phase and a “cloud” of proteins is released into a flight-tube in the mass spectrometer. The proteins are accelerated by an electric charge, and after passing through the tube, their “Time of Flight” is recorded. The proteins are then detected with a sensor that creates a spectrum which represents the protein makeup of each sample. Finally, the spectrum is compared to a known database of proteins, and according to the match, the microbial identification is completed.

For more information about the technology and clinical applications, please see an article by NRL's Director of Technical Operations, Albarah El-khani, published in Arab Health magazine.