System for Glycated Protein Detection

Abstract

A method of detecting the presence of glycated proteins or peptides (GPs) in a sample comprises carrying out the steps of assessing the sample for fluorescence, subjecting the sample to UV radiation, and reassessing the sample for an increase in fluorescence relative to any fluorescence assessed in said first assessing step, an increase in fluorescence at said reassessing step being indicative of the presence of GPs. The method may be useful for detecting disease such as diabetes.

1 . A method of detecting the presence of glycated proteins or peptides in a sample comprising carrying out the steps of assessing the sample for fluorescence, subjecting the sample to UV radiation, and reassessing the sample for an increase in fluorescence relative to any fluorescence assessed in said first assessing step, the presence of fluorescence at said assessing step and an increase in fluorescence at said reassessing step being indicative of the presence of glycated proteins or peptides. 
   
   
       2 . A method according to  claim 1  including subjecting the sample between assessments to UV radiation in the wavelength range 200-300 nm. 
   
   
       3 . A method according to  claim 1  including subjecting the sample between assessments to UV radiation in the wavelength range 250-260 nm. 
   
   
       4 . A method according to  claim 1  including subjecting the sample between assessments to UV radiation of about 254 nm wavelength. 
   
   
       5 . A method according to  claim 1  including subjecting the sample to UV radiation between assessments for less than 5 minutes. 
   
   
       6 . A method according to  claim 1  including measuring actual fluorescence of the sample in said assessment steps. 
   
   
       7 . A method according to  claim 6  including measuring any change in actual fluorescence between the assessment and the reassessment steps. 
   
   
       8 . A method according to  claim 1  comprising assessing and reassessing the fluorescence of the sample by reference to substantially only horizontally polarised fluorescent light. 
   
   
       9 . A method according to  claim 8  including causing the fluorescence to pass a filter oriented to pass substantially only horizontally polarised light. 
   
   
       10 . A method according to  claim 9  including in the assessment and reassessment steps exposing the sample to vertically polarised light as the excitation light. 
   
   
       11 . A method according to  claim 1  including spectrally resolving the fluorescence observed in the assessment and reassessment steps. 
   
   
       12 . A method according to  claim 11  including spectrally resolving the fluorescence observed in the assessment and reassessment steps and analyzing the shape of the fluorescence. 
   
   
       13 . A method according to  claim 1  including assessing the fluorescence of the sample, subjecting the sample to a pulse of UV radiation, and reassessing the fluorescence of the sample after a delay. 
   
   
       14 . A method according to  claim 13  including reassessing the fluorescence of the sample after a period of time substantially corresponding to the fluorescence lifetime of a class of glycated proteins or peptides. 
   
   
       15 . A method according to  claim 1  including assessing the fluorescence of the sample, subjecting the sample to a modulated UV signal, and reassessing the fluorescence of the sample for a modulated response. 
   
   
       16 . A method according to  claim 1  wherein the sample is a portion of skin of a living person or animal or a sample from a living person or animal. 
   
   
       17 . A method according to  claim 1  wherein the sample is of or from a person and including assessing the sample for the presence of glycated proteins or peptides as indicative of the presence of a disease in the person. 
   
   
       18 . A detector for detecting for the presence of glycated proteins or peptides in a sample comprising a UV source, a detection zone within which the sample may be placed or may pass, means for fluorescence analysis arranged to assess for the presence of glycated proteins or peptides by assessing the sample for fluorescence, subjecting the sample to UV radiation, and then reassessing the sample for an increase in fluorescence relative to any fluorescence assessed in said first assessing step, the presence of fluorescence at said assessing step and an increase in fluorescence at said reassessing step being indicative of the presence of glycated proteins or peptides. 
   
   
       19 . A detector according to  claim 18  wherein said source or sources of UV radiation is or are operable to irradiate the sample with UV radiation having a wavelength in the range of 200-300 nm as the radiation having the wavelength effective to cause fluorescence of the sample. 
   
   
       20 . A detector according to  claim 18  wherein said source or sources of UV radiation is or are operable to irradiate the sample with UV radiation having a wavelength of about 254 nm wavelength as the radiation having the wavelength effective to cause fluorescence of the sample. 
   
   
       21 . A detector according to  claim 18  wherein said radiation detector is arranged to detect substantially only horizontally polarized fluorescent radiation. 
   
   
       22 . A detector according to  claim 18  wherein said source or sources of UV radiation include a source of UV radiation operable to irradiate the sample with vertically polarized UV radiation as the radiation having the wavelength effective to cause fluorescence of the sample. 
   
   
       23 . A detector according to  claim 22  wherein said source or sources of UV radiation include a source of UV radiation operable to irradiate the sample with vertically polarized UV radiation as the radiation having the wavelength effective to cause fluorescence of the sample. 
   
   
       24 . A detector according to  claim 18  wherein said computer apparatus is arranged to spectrally resolve the first and second florescence signals. 
   
   
       25 . A detector according to  claim 18  wherein said computer apparatus is arranged to spectrally resolve the first and second fluorescence signals and analyse the shape of the fluorescence signals. 
   
   
       26 . A detector according to  claim 18  wherein said source or sources of UV radiation include a source of UV radiation operable to irradiate the sample with UV radiation having a wavelength effective to cause a photochemical change in the sample as a pulse of said UV radiation, and wherein said computer apparatus is arranged to record said second fluorescence signal after a time period from the end of said pulse of between 0.1-10 ns. 
   
   
       27 . A detector according to  claim 18  wherein said source or sources of UV radiation is or are operable to irradiate the sample with modulated UV radiation, and said radiation detector is arranged to detect a modulated fluorescence response. 
   
   
       28 . Apparatus for detecting glycated proteins or peptides in a sample comprising:
 a source or sources of UV radiation disposed for irradiating a sample and operable to irradiate the sample with UV radiation having a wavelength effective to cause fluorescence of the sample and subsequently with UV radiation having a wavelength effective to cause a photochemical change in the sample;   a radiation detector disposed for receiving fluorescence radiation from the sample when irradiated by said source or sources of UV radiation and generating a fluorescence signal upon receiving said fluorescence radiation; and   a computer apparatus operatively connected to said radiation detector or detectors and programmed to (a) record a first fluorescence signal from said radiation detector after the sample is first irradiated with UV radiation having a wavelength effective to cause fluorescence of the sample; (b) record a second fluorescence signal from said radiation detector after the sample is irradiated with UV radiation having a wavelength effective to cause a photochemical change in the sample and then re-irradiated with UV radiation having a wavelength effective to cause fluorescence of the sample; (c) compare said first and second fluorescence signals; and then (d) determine if there is any enhancement of the fluorescence of the sample to thereby detect the presence of glycated proteins or peptides.   
   
   
       29 . An apparatus according to  claim 28  wherein said source or sources of UV radiation comprise(s) first and second sources of UV radiation wherein the first source is operable to irradiate the sample with UV radiation having the wavelength effective to cause fluorescence of the sample and the second source is operable to irradiate the sample with UV radiation having the wavelength effective to cause a photochemical change in the sample, and
 said radiation detector comprises first and second radiation detectors wherein the first radiation detector is disposed for receiving the fluorescence radiation from the sample when irradiated by the first source UV radiation and generating the first fluorescence signal upon receiving said fluorescence radiation and the second radiation detector is disposed for receiving fluorescence radiation from the sample when re-irradiated by the second source of UV radiation and generating the second fluorescence signal upon receiving said fluorescence radiation.   
   
   
       30 . A method of diagnosing diabetes in a person or a likelihood of a person becoming diabetic, which comprises assessing the skin or a blood sample of the person for fluorescence, subjecting the skin or blood sample to UV radiation, and reassessing the skin or blood sample for an increase in fluorescence relative to any fluorescence assessed in said first assessing step, the presence of fluorescence at said assessing step and an increase in fluorescence at said reassessing step being indicative of the presence of diabetes or likelihood of the person becoming diabetic. 
   
   
       31 . A method according to  claim 17  wherein the disease is selected from any one or more of retinal dysfunction, cardiovascular disease, obesity, metabolic syndrome, diabetes, neurodegenerative disease, cancer, and renal disease. 
   
   
       32 . A method according to  claim 31  wherein the disease is diabetes.