sentence: RTA within different samples in an experiment were obtained using the following formula : RTA = { ( AS-AS0 ) / AS , IS } / { ( ATS8-ATS8 ,0 ) / ATS3 , IS } × 100 ( AS ; absorbance of sample , AS ,0 ; absorbance of heat-treated sample , AS , IS ; absorbance of internal standard ( IS ) of the sample , ATS8 ; absorbance of control template , ATS8 ,0 ; absorbance of lysis buffer , ATS8 , IS ; absorbance of IS of the control template ) .