The method 2, wherein said substance is selected from the group consisting of: urea, {HEAD ~ creatinine}, vitamin B12, {TAIL ~ beta two microglobuline} and glucose 
The method 2 , wherein said substance is selected from the group consisting of : urea , { HEAD ~ creatinine } , vitamin B12 , { TAIL ~ beta two microglobuline } and glucose
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH