Additionally, {TAIL ~ information} from multiple experiments is utilized to improve the accuracy of calling {HEAD ~ unknown bases} 
Additionally , { TAIL ~ information } from multiple experiments is utilized to improve the accuracy of calling { HEAD ~ unknown bases }
OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD