Periodic acid-schiff staining with detection in the infrared range

1. A method for detecting polysaccharides in a biological sample, which method consists essentially of the sequential steps of

subjecting the sample to Periodic Acid-Schiff staining to provide Periodic Acid-Schiff stained sample,

washing the sample to remove unreacted Schiff's reagents followed by detecting light fluorescing from said Periodic Acid-Schiff stained sample at a wavelength in the range from about 700 nM to 800 nM;

wherein the biological sample is isolated cells or tissue selected from the group consisting of liver, kidney, heart, brain and skeletal muscle.

2. The method of claim 1 , wherein the polysaccharide is glycogen.

3. The method of claim 1 , wherein the biological sample is derived from a human subject suspected of having a glycogen storage disease.

4. The method of claim 3 , wherein the glycogen storage disease is selected from the group consisting of Pompe disease; Cori's-Forbes' disease; Andersen's disease; Tauri's disease; McArdle's disease; Phosphorylase b Kinase deficiency (Glycogenosis type VIII); equine Glycogen Branching Deficiency; Phosphoglycerate kinase A-isoform deficiency (Glycogenosis IX); Phosphoglycerate M-mutase deficiency (Glycogenosis type X); triosephosphate isomerase (TIM) deficiency; pulmonary interstitial glycogenosis; diabetic nephropathy; and Lafora's disease (myoclonus epilepsy).

5. The method of claim 4 , wherein the glycogen storage disease is Pompe disease.

6. The method of claim 5 , wherein the glycogen storage disease is infantile-onset Pompe disease.

7. The method of claim 1 , which further comprises quantitating the level of polysaccharides present in the biological sample by comparing the amount of the light fluorescing from the periodic Acid-Schiff stained sample at a wavelength in the range from about 700 nM to 800 nM with that light fluorescing from standards of known quantities of polysaccharides.

8. A method for detecting glycogen in a biological sample from a subject having or suspected of having Pompe disease, which method consists essentially of the sequential steps of

subjecting the sample to Periodic Acid-Schiff staining to provide Periodic Acid-Schiff stained sample,

washing the sample to remove unreacted Schiff's reagents followed by detecting light fluorescing from said Periodic Acid-Schiff stained sample at a wavelength in the range from about 700 nM to 800 nM;

wherein the biological sample is isolated cells or tissue selected from the group consisting of liver, kidney, heart, brain and skeletal muscle.

9. The method of claim 8 , which further comprises quantitating the level of polysaccharides present in the biological sample by comparing the amount of the light fluorescing from the periodic Acid-Schiff stained sample at a wavelength in the range from about 700 nM to 800 nM with that light fluorescing from standards of known quantities of glycogen.

10. A method of monitoring the efficacy of treatment of a subject being treated for a glycogen storage disease, which method comprises

i) detecting glycogen in a first biological sample derived from the subject prior to initiation of treatment according to the method of claim 1 ;

ii) detecting glycogen in a second biological sample derived from the subject following initiation of treatment according to the method of claim 1 ;

iii) quantitating the levels of glycogen in the two samples; and

iv) comparing the level of glycogen in the first sample with the level of glycogen in the second sample;

wherein a reduction in the level of glycogen in the second sample indicates that the treatment is effective.

11. The method of claim 10 , wherein the glycogen storage disease is Pompe disease.