Amyloid beta oligomer detection method, amyloid beta oligomer detection device, and amyloid beta oligomer detection program

Abstract

The present invention relates to a method for detecting an amyloid β oligomer which includes a test sample and thioflavin T are brought into contact with each other, fluorescence of the thioflavin T is measured to obtain time-resolved fluorescence spectra, the time-resolved fluorescence spectrum of time period t 1 to t 2 and the time-resolved fluorescence spectrum of time period t 3 to t 4 are respectively normalized to obtain normalized spectra (t 1 <t 2 ≤t 3 <t 4 ), and determination is made to confirm the presence or absence of an amyloid β oligomer in the test sample on the basis of the two normalized spectra, and shifting of the normalized spectrum of time period t 3 to t 4 towards the low wavelength side in comparison to the normalized spectrum of time period t 1 to t 2 indicates the presence of an amyloid β oligomer in the test sample.

1 . A device for detecting an amyloid β oligomer, comprising:
 an acquisition means for acquiring time-resolved fluorescence spectrum data of thioflavin T brought into contact with a test sample; 
 a calculation means for calculating normalized spectra by normalizing respectively the time-resolved fluorescence spectrum of time period t 1  to t 2  and the time-resolved fluorescence spectrum of time period t 3  to t 4  from the acquired time-resolved fluorescence spectrum data; 
 a comparison means for comparing the two normalized spectra; and 
 a determination means for determining the presence or absence of an amyloid β oligomer in the test sample based on a comparison result, 
 wherein t 1 <t 2 ≤t 3 <t 4  and 
 wherein shifting of the normalized spectrum of time period t 3  to t 4  towards a low wavelength side in comparison to the normalized spectrum of time period t 1  to t 2  indicates the presence of an amyloid β oligomer in the test sample. 
 
     
     
         2 . A program for detecting an amyloid β oligomer arranged to make a computer function as:
 an acquisition means for acquiring time-resolved fluorescence spectrum data of thioflavin T brought into contact with a test sample; 
 a calculation means for calculating normalized spectra by normalizing respectively the time-resolved fluorescence spectrum of time period t 1  to t 2  and the time-resolved fluorescence spectrum of time period t 3  to t 4  from the acquired time-resolved fluorescence spectrum data, wherein t 1 <t 2 ≤t 3 <t 4 ; 
 a comparison means for comparing the two normalized spectra; and 
 a determination means for determining the presence or absence of an amyloid β oligomer in the test sample based on a comparison result, wherein shifting of the normalized spectrum of time period t 3  to t 4  towards a low wavelength side in comparison to the normalized spectrum of time period t 1  to t 2  indicates the presence of an amyloid β oligomer in the test sample. 
 
     
     
         3 . A computer-readable storage medium storing the program for detecting an amyloid β oligomer according to  claim 2 . 
     
     
         4 . The device according to  claim 1 ,
 wherein when the fluorescence ratio s 1  is less than 1, it is determined that an amyloid β oligomer is present, or, when the fluorescence ratio s 1  is 1 or more, it is determined that an amyloid β oligomer is absent,
   Fluorescence ratio s1=(Fluorescence intensity of normalized spectrum of time period t3 to t4 at wavelength λ1)/(Fluorescence intensity of normalized spectrum of time period t1 to t2 at wavelength λ1),
 
   wherein λ 1  is more than 480 nm.   
     
     
         5 . The device according to  claim 1 ,
 wherein when the fluorescence ratio s 2  is more than 1, it is determined that an amyloid β oligomer is present, or, when the fluorescence ratio s 2  is 1 or less, it is determined that an amyloid β oligomer is absent,
   Fluorescence ratio  s 2=(Fluorescence intensity of normalized spectrum of time period t3 to t4 at wavelength λ2)/(Fluorescence intensity of normalized spectrum of time period t1 to t2 at wavelength λ2),
 
   wherein λ 2  is less than 480 nm.   
     
     
         6 . The device according to  claim 1 ,
 wherein when the peak top wavelength of the normalized spectrum of time period t 3  to t 4  is shorter than the peak top wavelength of the normalized spectrum of time period t 1  to t 2 , it is determined that an amyloid β oligomer is present, or, when the peak top wavelength of the normalized spectrum of time period t 3  to t 4  is the same or longer than the peak top wavelength of the normalized spectrum of time period t 1  to t 2 , it is determined that an amyloid β oligomer is absent.   
     
     
         7 . The program according to  claim 2 ,
 wherein when the fluorescence ratio s 1  is less than 1, it is determined that an amyloid β oligomer is present, or, when the fluorescence ratio s 1  is 1 or more, it is determined that an amyloid β oligomer is absent,
   Fluorescence ratio  s 1=(Fluorescence intensity of normalized spectrum of time period t3 to t4 at wavelength λ1)/(Fluorescence intensity of normalized spectrum of time period t1 to t2 at wavelength λ1),
 
   wherein λ 1  is more than 480 nm.   
     
     
         8 . The program according to  claim 2 ,
 wherein when the fluorescence ratio s 2  is more than 1, it is determined that an amyloid β oligomer is present, or, when the fluorescence ratio s 2  is 1 or less, it is determined that an amyloid β oligomer is absent,
   Fluorescence ratio  s 2=(Fluorescence intensity of normalized spectrum of time period t3 to t4 at wavelength λ2)/(Fluorescence intensity of normalized spectrum of time period t1 to t2 at wavelength λ2),
 
   wherein λ 2  is less than 480 nm.   
     
     
         9 . The program according to  claim 2 ,
 wherein when the peak top wavelength of the normalized spectrum of time period t 3  to t 4  is shorter than the peak top wavelength of the normalized spectrum of time period t 1  to t 2 , it is determined that an amyloid β oligomer is present, or, when the peak top wavelength of the normalized spectrum of time period t 3  to t 4  is the same or longer than the peak top wavelength of the normalized spectrum of time period t 1  to t 2 , it is determined that an amyloid β oligomer is absent.