Cell identification device and program

• US 10,385,379 B2
• Filed: 10/17/2012
• Issued: 08/20/2019
• Est. Priority Date: 10/18/2011
• Status: Active Grant

• Current Assignee: Shimadzu Corporation
• Original Assignee: Shimadzu Corporation
• Inventors: Ojima, Noriyuki, Ogata, Koretsugu, Shima, Keisuke, Tamura, Hiroto, Hosoda, Akifumi, Hotta, Yudai
• Primary Examiner(s): Satanovsky, Alexander
• Assistant Examiner(s): Fairbanks, Brent A.
• Application Number:
  US14/352,496
• Publication Number:
  US 20140288852A1
• Time in Patent Office: 2,498 Days
• Field of Search: None
• CPC Class Codes: C12Q 1/04 Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor C12Q1/6897 takes precedence
• CPC Class Codes: G01N 15/10 Investigating individual particles
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G01N 33/48735 Investigating suspensions of cells, e.g. measuring microbe concentration by chemical means C12Q1/04; colony counters C12M1/34; concentration of particle suspensions in general G01N15/06
• CPC Class Codes: G16C 20/20 Identification of molecular entities, parts thereof or of chemical compositions
• CPC Class Codes: H01J 49/025 Detectors specially adapted to particle spectrometers data acquisition H01J49/0036; detectors per se G01T, e.g. G01T1/28, G01T1/29

Abstract

An apparatus that identifies the type of a test cell based on a result obtained by performing mass spectrometry on the test cell includes a higher-level database, which contains mass lists that each list ion mass values of constituent components of a known cell, and a lower-level database, which contains partial mass lists that each list only strain-specific ion mass values out of the ion mass values. The higher-level database is first searched for a test mass list which is created from the result of the mass spectrometry performed on the test cell, and based on a result of the search, an organism species to be searched in the following search operation is determined. Mass values common to the organism species are subsequently deleted from the mass list for the test cell, and the mass list having undergone the deletion operation is used to search the lower-level database.

Claims

1. A cell identification apparatus, comprising:

an identification unit that includes a storage section and a computation section and identifies a type of a test cell based on a result obtained by performing mass spectrometry on the test cell, wherein

the storage section stores a first database containing mass lists for a plurality of known cells, and

the computation section includes a processor configured to;

a) create a test mass list including ion mass values or molecular weights of constituent components of the test cell based on detection signals obtained from a detector;

b) search the first database for mass lists that correspond to the test mass list;

c) determine, based on a result of the search for the mass lists, one classification group corresponding to the test mass list from among classification groups of the mass lists as a classification group to which the test cell belongs;

d) create a test partial mass list from the test mass list by deleting ion mass values or molecular weights common to the classification group to which the test cell belongs from the test mass list;

e) create a second database containing partial mass lists which are obtained by deleting, from the mass lists for known cells belonging to the classification group to which the test cell belongs, ion mass values or molecular weights common to the classification group to which the test cell belongs;

f) search the second database for at least one partial mass list having similarities higher than a predetermined threshold to the test partial mass list; and

an output device that outputs a result of searching the second database for the at least one partial mass list.

2. The cell identification apparatus according to claim 1, wherein

the storage section further comprises a variation database containing information on variations that may occur in a base sequence or an amino acid sequence, and

the processor further obtains information on the variations from the variation database and searches, for the test partial mass list, partial mass lists contained in the second database whose ion mass values or molecular weights having been changed to ion mass values or molecular weights after the variations occur based on the information.

3. A non-transitory computer readable medium recording a program that makes a computer function according to a method, comprising:

creating a test mass list including ion mass values or molecular weights of constituent components of a test cell;

searching a first database for mass lists that correspond to the test mass list, the first database containing mass lists for a plurality of known cells, each of the mass lists listing ion mass values or molecular weights of constituent components of each of the plurality of known cells,

determining, based on a result of the search for the mass lists, one classification group corresponding to the test mass list from among the classification groups of the mass lists as a classification group to which the test cell belongs,

creating a test partial mass list from the test mass list by deleting ion mass values or molecular weights common to the classification group to which the test cell belongs determined in the step of determining the classification group to which the test cell belongs from the test mass list,

creating a second database containing partial mass lists which are obtained by deleting, from the mass lists for known cells belonging to a classification group to which the test cell belongs determined by the classification group determiner, ion mass values or molecular weights common to the classification group to which the test cell belongs determined by the classification group determiner; and

searching the second database for at least one partial mass list that has similarities higher than a predetermined threshold to the created test partial mass list, the second database containing partial mass lists for the plurality of known cells, each of the partial mass lists listing, among the ion mass values or molecular weights of the constituent components of the known cells, ion mass values or molecular weights other than ion mass values or molecular weights common to classification groups in a predetermined class to which the known cells belong; and

outputting a result of searching the second database for the at least one partial mass list.