My dear Bandyopadhyay ji, Please pull out the attached links they will be helpful to you. have a nice day. regards

http://pubs.aic.ca/doi/abs/10.4141/S04-003

http://link.springer.com/article/10.1023/A:1004347701584

http://www.sciencedirect.com/science/article/pii/S0038071706001167

http://www.sciencedirect.com/science/article/pii/S0038071704002718

Dear Bandyopadhyay ji, 

I am solely agree with the answer and articles given by the Sarwan Kumar Dubey. Kindly get more focus on the linked article. It has explain the things clearly.  

Good Luck

http://link.springer.com/article/10.1023/A:1004347701584

Sir the attached papers are sufficient....I did according to the methods mentioned in those paper. Only you need to adjust the  numbers of time to extract the Total Glomalin related soil protein (TGRSP) as per the soil you are using. All the best

I believe that the information provided by previous colleagues would technically be very helpful. My concern is reliability of common method (Bradford protein assay) which may not work properly in the presence of high organic matter input (or background) as indicated by Gillespie et al 2011 (Glomalin-related soil protein contains non-mycorrhizal-related heat-stable proteins, lipids and humic materials Soil Biology and Biochemistry, 43: 766-777.) I would like to suggest you to take these bottlenecks into your consideration. Best wishes