WEBVTT

00:00:08.241 --> 00:00:09.342
The classic way to

00:00:09.342 --> 00:00:14.214
identify microorganisms includes
using different biochemical reactions

00:00:14.214 --> 00:00:17.484
and stains to distinguish
one organism from another.

00:00:18.518 --> 00:00:22.622
Some of these tasks can be performed
quickly and are still routinely used.

00:00:23.223 --> 00:00:26.326
However, many biochemical tests require

00:00:26.326 --> 00:00:29.662
several hours of incubation
before they can be interpreted.

00:00:30.497 --> 00:00:32.399
Patient results could be delayed

00:00:32.399 --> 00:00:35.402
if the growth of the organism
is slower than anticipated.

00:00:36.269 --> 00:00:40.173
Molotov,
which stands for matrix assisted laser

00:00:40.173 --> 00:00:44.577
desorption ionization
time of flight mass spectrometry,

00:00:45.178 --> 00:00:49.416
is a diagnostic instrument
that can be used in clinical settings

00:00:49.783 --> 00:00:52.886
and allows for the rapid identification
of organisms.

00:00:53.386 --> 00:00:57.690
A small portion of the bacterial colony
is placed onto a steel plate.

00:00:58.124 --> 00:01:01.261
The sample is then overlaid
with a matrix compound.

00:01:01.895 --> 00:01:05.131
After the matrix is dried,
the plate is inserted

00:01:05.131 --> 00:01:08.701
into the instrument
where a laser ionizes the sample.

00:01:09.702 --> 00:01:10.437
As the sample

00:01:10.437 --> 00:01:13.440
molecules become vibrationally excited,

00:01:13.540 --> 00:01:17.844
they vaporize into the vacuum
while being ionized at the same time.

00:01:18.545 --> 00:01:23.283
The detected biomolecules are identified
using the unique pattern produced

00:01:23.283 --> 00:01:28.288
by proteins of the microorganism,
which is known as a spectrum fingerprint.

00:01:28.922 --> 00:01:34.427
Each spectrum contains a pattern of peaks
that is unique to a specific genus.

00:01:34.427 --> 00:01:36.663
Species and strains.

00:01:36.663 --> 00:01:41.301
The mALDI TOF instrument uses an algorithm
to match the test results

00:01:41.301 --> 00:01:44.437
to a library of fingerprints
of known organisms.

00:01:45.138 --> 00:01:47.874
MALDI TOF is not a reliable method

00:01:47.874 --> 00:01:50.810
for identifying unusual organisms,

00:01:50.810 --> 00:01:54.347
because they need to be part
of the database of validated results

00:01:54.581 --> 00:01:58.685
for accurate identification,
and unusual organisms

00:01:59.152 --> 00:02:03.289
may not be included in the available
library of validated organisms.

00:02:03.957 --> 00:02:07.227
It also may have some difficulty
differentiating closely

00:02:07.227 --> 00:02:11.464
related organisms
such as E.coli and Shigella species.

00:02:12.031 --> 00:02:16.035
Overall, mALDI TOF is an efficient
and cost effective tool

00:02:16.269 --> 00:02:20.306
to identify microorganisms
to the genus and species level.