diff --git a/DESCRIPTION b/DESCRIPTION
index 2f06b17..f36d02c 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Package: fetchNOMe
 Type: Package
 Title: Package for fast and convenient retrieval of NOMe-seq data from BAM files
-Version: 0.1
-Date: 2023-10-02
+Version: 0.2
+Date: 2024-05-09
 Authors@R: person(given = "Evgeniy A.", family="Ozonov", email = "evgeniy.ozonov@fmi.ch", role = c("aut", "cre"))
 Description: This R package is tailored for fast and convenient retrieval of NOMe-seq data from BAM files aligned with QuasR, Bismark and BISCUIT. 
 License: MIT + file LICENSE
diff --git a/R/RcppExports.R b/R/RcppExports.R
index 4b7485d..d3b9c92 100644
--- a/R/RcppExports.R
+++ b/R/RcppExports.R
@@ -1,7 +1,7 @@
 # Generated by using Rcpp::compileAttributes() -> do not edit by hand
 # Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393
 
-fetch_data_matrix_from_bams_cpp <- function(whichContext, infiles, regionChr, regionStart, regionEnd, seqstring, seqStart, seqEnd, remove_nonunique, clip_until_nbg, max_protect_frac, max_bisC_meth, min_bisC_size, mapqMin, mapqMax) {
-    .Call(`_fetchNOMe_fetch_data_matrix_from_bams_cpp`, whichContext, infiles, regionChr, regionStart, regionEnd, seqstring, seqStart, seqEnd, remove_nonunique, clip_until_nbg, max_protect_frac, max_bisC_meth, min_bisC_size, mapqMin, mapqMax)
+fetch_data_matrix_from_bams_cpp <- function(whichContext, infiles, regionChr, regionStart, regionEnd, seqstring, seqStart, seqEnd, remove_nonunique, clip_until_nbg, max_protect_frac, max_bisC_meth, min_bisC_size, mapqMin, mapqMax, alignerUsed) {
+    .Call(`_fetchNOMe_fetch_data_matrix_from_bams_cpp`, whichContext, infiles, regionChr, regionStart, regionEnd, seqstring, seqStart, seqEnd, remove_nonunique, clip_until_nbg, max_protect_frac, max_bisC_meth, min_bisC_size, mapqMin, mapqMax, alignerUsed)
 }
 
diff --git a/R/get_data_matrix_from_bams.R b/R/get_data_matrix_from_bams.R
index 3901f8a..5953c21 100644
--- a/R/get_data_matrix_from_bams.R
+++ b/R/get_data_matrix_from_bams.R
@@ -16,7 +16,7 @@
 #' \item{"otherC"}{methylation states of all other cytosines which do not fall into above categories.}
 #' \item{"allC"}{methylation states of all cytosines combined.}
 #' }
-#' 
+#' @param alignerUsed \code{character} that defines which aligner was used to generate BAM files. Currently supported aligners are QuasR, Bismark and BISQUIT.
 #' @param collapseBySample \code{logical} indicating whether to collapse counts for bam files with same \code{samplenames}. If \code{FALSE} prefix \code{s} followed by index is added to \code{samplenames}.
 #' @param remove_nonunique \code{logical} if \code{TRUE} only unique fragments are analyzed. Uniqueness is defined by fragments start, end and methylation states of all cytosines. 
 #' @param clip_until_nbg \code{integer} controlling clipping partial footprints at both ends of fragments. Namely, protected states are erased from each end until \code{clip_until_nbg} unprotected states are met.
@@ -53,6 +53,7 @@ get_data_matrix_from_bams <- function(bamfiles,
 																			regions,
 																			genome,
 																			whichContext = c("GCH","WCG","bisC","otherC", "allC"),
+																			alignerUsed = c("QuasR","Bismark","BISQUIT"),
 																			collapseBySample = TRUE,
 																			remove_nonunique = TRUE,
 																			clip_until_nbg  = 1L,
@@ -85,6 +86,11 @@ get_data_matrix_from_bams <- function(bamfiles,
 	
 	whichContext <- match.arg(whichContext)
 	
+	alignerUsed <- match.arg(alignerUsed)
+	
+	message(paste0("Fetching data from BAM files generated by ",alignerUsed,"."))
+	
+	
 	## remove metadata from regions
 	GenomicRanges::mcols(regions) <- NULL
 	
@@ -132,7 +138,8 @@ get_data_matrix_from_bams <- function(bamfiles,
 																																			 																						 max_bisC_meth = max_bisC_meth,
 																																			 																						 min_bisC_size = min_bisC_size,
 																																			 																						 mapqMin = mapqMin,
-																																			 																						 mapqMax = mapqMax)
+																																			 																						 mapqMax = mapqMax,
+																																			 																						 alignerUsed = alignerUsed)
 																																			 	
 																																			 	data_mat <- outlist[["DataMatrix"]]
 																																			 	# invert rows if strand is -
diff --git a/man/get_data_matrix_from_bams.Rd b/man/get_data_matrix_from_bams.Rd
index 580e187..08c6d32 100644
--- a/man/get_data_matrix_from_bams.Rd
+++ b/man/get_data_matrix_from_bams.Rd
@@ -10,6 +10,7 @@ get_data_matrix_from_bams(
   regions,
   genome,
   whichContext = c("GCH", "WCG", "bisC", "otherC", "allC"),
+  alignerUsed = c("QuasR", "Bismark", "BISQUIT"),
   collapseBySample = TRUE,
   remove_nonunique = TRUE,
   clip_until_nbg = 1L,
@@ -40,6 +41,8 @@ get_data_matrix_from_bams(
 \item{"allC"}{methylation states of all cytosines combined.}
 }}
 
+\item{alignerUsed}{\code{character} that defines which aligner was used to generate BAM files. Currently supported aligners are QuasR, Bismark and BISQUIT.}
+
 \item{collapseBySample}{\code{logical} indicating whether to collapse counts for bam files with same \code{samplenames}. If \code{FALSE} prefix \code{s} followed by index is added to \code{samplenames}.}
 
 \item{remove_nonunique}{\code{logical} if \code{TRUE} only unique fragments are analyzed. Uniqueness is defined by fragments start, end and methylation states of all cytosines.}
diff --git a/src/RcppExports.cpp b/src/RcppExports.cpp
index d0644a3..7e43d5d 100644
--- a/src/RcppExports.cpp
+++ b/src/RcppExports.cpp
@@ -12,8 +12,8 @@ Rcpp::Rostream<false>& Rcpp::Rcerr = Rcpp::Rcpp_cerr_get();
 #endif
 
 // fetch_data_matrix_from_bams_cpp
-Rcpp::List fetch_data_matrix_from_bams_cpp(const Rcpp::CharacterVector& whichContext, const Rcpp::CharacterVector& infiles, const Rcpp::CharacterVector& regionChr, const Rcpp::IntegerVector& regionStart, const Rcpp::IntegerVector& regionEnd, const Rcpp::CharacterVector& seqstring, const Rcpp::IntegerVector& seqStart, const Rcpp::IntegerVector& seqEnd, const Rcpp::LogicalVector& remove_nonunique, const Rcpp::IntegerVector& clip_until_nbg, const Rcpp::NumericVector& max_protect_frac, const Rcpp::NumericVector& max_bisC_meth, const Rcpp::IntegerVector& min_bisC_size, const Rcpp::IntegerVector& mapqMin, const Rcpp::IntegerVector& mapqMax);
-RcppExport SEXP _fetchNOMe_fetch_data_matrix_from_bams_cpp(SEXP whichContextSEXP, SEXP infilesSEXP, SEXP regionChrSEXP, SEXP regionStartSEXP, SEXP regionEndSEXP, SEXP seqstringSEXP, SEXP seqStartSEXP, SEXP seqEndSEXP, SEXP remove_nonuniqueSEXP, SEXP clip_until_nbgSEXP, SEXP max_protect_fracSEXP, SEXP max_bisC_methSEXP, SEXP min_bisC_sizeSEXP, SEXP mapqMinSEXP, SEXP mapqMaxSEXP) {
+Rcpp::List fetch_data_matrix_from_bams_cpp(const Rcpp::CharacterVector& whichContext, const Rcpp::CharacterVector& infiles, const Rcpp::CharacterVector& regionChr, const Rcpp::IntegerVector& regionStart, const Rcpp::IntegerVector& regionEnd, const Rcpp::CharacterVector& seqstring, const Rcpp::IntegerVector& seqStart, const Rcpp::IntegerVector& seqEnd, const Rcpp::LogicalVector& remove_nonunique, const Rcpp::IntegerVector& clip_until_nbg, const Rcpp::NumericVector& max_protect_frac, const Rcpp::NumericVector& max_bisC_meth, const Rcpp::IntegerVector& min_bisC_size, const Rcpp::IntegerVector& mapqMin, const Rcpp::IntegerVector& mapqMax, const Rcpp::CharacterVector& alignerUsed);
+RcppExport SEXP _fetchNOMe_fetch_data_matrix_from_bams_cpp(SEXP whichContextSEXP, SEXP infilesSEXP, SEXP regionChrSEXP, SEXP regionStartSEXP, SEXP regionEndSEXP, SEXP seqstringSEXP, SEXP seqStartSEXP, SEXP seqEndSEXP, SEXP remove_nonuniqueSEXP, SEXP clip_until_nbgSEXP, SEXP max_protect_fracSEXP, SEXP max_bisC_methSEXP, SEXP min_bisC_sizeSEXP, SEXP mapqMinSEXP, SEXP mapqMaxSEXP, SEXP alignerUsedSEXP) {
 BEGIN_RCPP
     Rcpp::RObject rcpp_result_gen;
     Rcpp::RNGScope rcpp_rngScope_gen;
@@ -32,13 +32,14 @@ BEGIN_RCPP
     Rcpp::traits::input_parameter< const Rcpp::IntegerVector& >::type min_bisC_size(min_bisC_sizeSEXP);
     Rcpp::traits::input_parameter< const Rcpp::IntegerVector& >::type mapqMin(mapqMinSEXP);
     Rcpp::traits::input_parameter< const Rcpp::IntegerVector& >::type mapqMax(mapqMaxSEXP);
-    rcpp_result_gen = Rcpp::wrap(fetch_data_matrix_from_bams_cpp(whichContext, infiles, regionChr, regionStart, regionEnd, seqstring, seqStart, seqEnd, remove_nonunique, clip_until_nbg, max_protect_frac, max_bisC_meth, min_bisC_size, mapqMin, mapqMax));
+    Rcpp::traits::input_parameter< const Rcpp::CharacterVector& >::type alignerUsed(alignerUsedSEXP);
+    rcpp_result_gen = Rcpp::wrap(fetch_data_matrix_from_bams_cpp(whichContext, infiles, regionChr, regionStart, regionEnd, seqstring, seqStart, seqEnd, remove_nonunique, clip_until_nbg, max_protect_frac, max_bisC_meth, min_bisC_size, mapqMin, mapqMax, alignerUsed));
     return rcpp_result_gen;
 END_RCPP
 }
 
 static const R_CallMethodDef CallEntries[] = {
-    {"_fetchNOMe_fetch_data_matrix_from_bams_cpp", (DL_FUNC) &_fetchNOMe_fetch_data_matrix_from_bams_cpp, 15},
+    {"_fetchNOMe_fetch_data_matrix_from_bams_cpp", (DL_FUNC) &_fetchNOMe_fetch_data_matrix_from_bams_cpp, 16},
     {NULL, NULL, 0}
 };
 
diff --git a/src/fetch_data_from_bam.cpp b/src/fetch_data_from_bam.cpp
index 796468f..ed3b869 100644
--- a/src/fetch_data_from_bam.cpp
+++ b/src/fetch_data_from_bam.cpp
@@ -5,6 +5,7 @@ bool fetch_data_from_bam(const string& bamfile,
                          const string& regionChr,
                          const int& regionStart,
                          const int& regionEnd,
+                         const alignerType& aligner,
                          obj_pnts* pnts){
 	
 	
@@ -26,8 +27,27 @@ bool fetch_data_from_bam(const string& bamfile,
 	if(regionChr.compare(fin->header->target_name[tid]) != 0)
 		Rcpp::stop("could not find target '" + regionChr + "' in bam header of " + bamfile + ".\n");
 	
-	// call collectRegionData on store alignments in region
-	bam_fetch(fin->x.bam, idx, tid, regionStart, regionEnd, pnts, &collectRegionData);
+	
+	// define a pointer to a callback retrival function
+	int (*collectRegionData)(const bam1_t *hit, void *data);
+	
+	// choose callback function for data parsing based on aligner used
+	switch(aligner) {
+	case QuasR:
+	  collectRegionData = &collectRegionData_QsBism;
+	  break;
+	case Bismark:
+	  collectRegionData = &collectRegionData_QsBism;
+	  break;
+	case BISQUIT:
+	  collectRegionData = &collectRegionData_Bisq;
+	  break;
+	default:
+	  Rcpp::stop("Only alignments generated by QuasR, Bismark or BISQUIT can be analyzed\n");
+	}
+	
+	// call corresponding retrieval function to store alignments in region
+	bam_fetch(fin->x.bam, idx, tid, regionStart, regionEnd, pnts, collectRegionData);
 	
 	// clean bam file objects
 	bam_index_destroy(idx);
@@ -36,8 +56,8 @@ bool fetch_data_from_bam(const string& bamfile,
 	return(1);
 }
 
-
-static int collectRegionData(const bam1_t *hit, void *data) { // bam_fetch callback function that parses XM tag in bismark bam and adds cooccurrence counts
+// bam_fetch callback function for methyl calling and data storing for BAMs produced by QuasR and Bismark
+static int collectRegionData_QsBism(const bam1_t *hit, void *data) { 
 	
 	static obj_pnts *pdata = NULL;
 	
@@ -67,7 +87,9 @@ static int collectRegionData(const bam1_t *hit, void *data) { // bam_fetch callb
 	} else{ // parsing first mate or SE data, strand determined by read itself
 		msmType = is_read_rev ? GtoA : CtoT;
 	}
-	// Rcpp::Rcout<<"msmType="<<msmType<<endl;
+	
+	// for testing only
+	//Rcpp::Rcout<<"qname="<<qname<<"\nis_second="<<is_second<<"\nis_read_rev="<<is_read_rev<<"\nis_mate_rev="<<is_mate_rev<<"\nmsmType="<<msmType<<endl;
 	// 
 	// // for testing only
 	// fragData frg;
@@ -175,6 +197,172 @@ static int collectRegionData(const bam1_t *hit, void *data) { // bam_fetch callb
 }
 
 
+
+// bam_fetch callback function for methyl calling and data storing for BAMs produced by BISQUIT
+static int collectRegionData_Bisq(const bam1_t *hit, void *data) { 
+  
+  static obj_pnts *pdata = NULL;
+  
+  pdata = (obj_pnts*) data;
+  
+  
+  // check if alignment is valid
+  if(!isValidAln(hit,pdata))
+    return(0);
+  // for testing only
+  //print_bs_alignment(hit,pdata);
+  
+  // parse alignment and create vectors for regData
+  string qname = string(bam1_qname(hit)); // frag name
+  uint32_t *cigar = bam_get_cigar(hit); // cigar array
+  uint8_t *hitseq = bam1_seq(hit); // query sequence
+  int ref_start = hit -> core.pos; // leftmost position in reference
+  int ref_end = bam_calend(&(hit->core),cigar); // rightmost position in reference
+  bool is_read_rev = bam_is_rev(hit); // is read on "+" strand
+  bool is_mate_rev = bam_is_mrev(hit);
+  bool is_second = bam_is_second(hit); // is it a second mate
+  
+  // extract YD tag
+  uint8_t* ydTag = bam_aux_get(hit, "YD");
+  char ydValue;
+  if (ydTag) {
+    // The first byte is the type identifier, followed by the value
+    char type = bam_aux_type(ydTag);
+    if (type == 'A') {
+      // Get value
+      ydValue = bam_aux2A(ydTag);
+      
+    } else {
+      Rcpp::Rcout << "Unexpected type for YD tag" << std::endl;
+    }
+    
+  } else {
+    Rcpp::Rcout << "No YD tag found. Either BAM file is corrupted or generated not by BISQUIT." << std::endl;
+  }
+  
+  
+  // choose which mismatches to analyze
+  seekMismType msmType;
+  if(ydValue == 'f'){
+    msmType = CtoT;
+  } else if(ydValue == 'r'){
+    msmType = GtoA;
+  } else {
+    Rcpp::Rcout << "Unexpected value for YD tag: " <<ydValue<< std::endl;
+  }
+  
+  // for testing only
+  // Rcpp::Rcout<<"qname="<<qname<<"\nis_second="<<is_second<<"\nis_read_rev="<<is_read_rev<<"\nis_mate_rev="<<is_mate_rev<<"\nmsmType="<<msmType<<"\nYD tag="<<ydValue<<endl;
+  // 
+  // // for testing only
+  // fragData frg;
+  
+  // go across contexts and add data
+  vector<fragMapType > context_vec = {GCH, WCG, bisC, otherC};
+  for(int i = 0; i < context_vec.size(); ++i){
+    // get positions for the context in reference
+    vector<int> cntx_rpos_vec = pdata->refseq_info->getPositionsBetween(ref_start,ref_end,context_vec[i], msmType == CtoT);
+    
+    vector<int > rpos_vec;
+    vector<bool > dat_vec;
+    vector<bool > isplusstrand_vec;
+    
+    for(int cind = 0; cind < cntx_rpos_vec.size(); ++cind){
+      
+      // get query position
+      int qpos = _fromRefToQueryPos(ref_start,
+                                    cntx_rpos_vec[cind],
+                                                 hit->core.n_cigar,
+                                                 cigar);
+      // get nucleotide in query
+      string qseq = nt16_table[bam1_seqi(hitseq, qpos)];
+      
+      // check if C->T mismatch if msmType == CtoT or GtoA otherwise. query on - in BAM are reverse complement
+      switch(msmType) {
+      case CtoT:
+      {
+        if(qseq == "C"){ // methylated or unprotected
+        // add position on reference
+        rpos_vec.push_back(cntx_rpos_vec[cind]);
+        // add data
+        dat_vec.push_back(context_vec[i] == GCH ? 0 : 1);
+        // add strand
+        isplusstrand_vec.push_back(!is_read_rev);
+        
+      } else if(qseq == "T"){ // unmethylated or protected
+        // add position on reference
+        rpos_vec.push_back(cntx_rpos_vec[cind]);
+        // add data
+        dat_vec.push_back(context_vec[i] == GCH ? 1 : 0);
+        // add strand
+        isplusstrand_vec.push_back(!is_read_rev);
+      }
+      break;
+      }
+      case GtoA:
+      {
+        if(qseq == "G"){ // methylated or unprotected
+        // add position on reference
+        rpos_vec.push_back(cntx_rpos_vec[cind]);
+        // add data
+        dat_vec.push_back(context_vec[i] == GCH ? 0 : 1);
+        // add strand
+        isplusstrand_vec.push_back(!is_read_rev);
+        
+      } else if(qseq == "A"){ // unmethylated or protected
+        // add position on reference
+        rpos_vec.push_back(cntx_rpos_vec[cind]);
+        // add data
+        dat_vec.push_back(context_vec[i] == GCH ? 1 : 0);
+        // add strand
+        isplusstrand_vec.push_back(!is_read_rev);
+      }
+      
+      break;
+      }
+      }
+      
+      
+    }
+    
+    
+    
+    
+    // add data for the current context into regionData
+    pdata->reg_data->addFragContextData(pdata->prefix,
+                                        pdata->prefix + qname,
+                                        ref_start,
+                                        ref_end,
+                                        rpos_vec,
+                                        dat_vec,
+                                        isplusstrand_vec,
+                                        is_second,
+                                        context_vec[i]);
+    
+    // for testing only
+    // 		frg.addData(ref_start,
+    //               ref_end,
+    //               rpos_vec,
+    //               dat_vec,
+    //               isplusstrand_vec,
+    //               is_second,
+    //               context_vec[i]);
+    
+  }
+  
+  
+  
+  
+  
+  
+  return(0);
+  
+}
+
+
+
+
+
 // checks validity of an alignment
 bool isValidAln(const bam1_t *hit,const obj_pnts* pdata){
 	
diff --git a/src/fetch_data_from_bam.h b/src/fetch_data_from_bam.h
index c8e1f3a..28b2ba2 100644
--- a/src/fetch_data_from_bam.h
+++ b/src/fetch_data_from_bam.h
@@ -40,10 +40,16 @@ bool fetch_data_from_bam(const string& bamfile,
                          const string& regionChr,
                          const int& regionStart,
                          const int& regionEnd,
+                         const alignerType& aligner,
                          obj_pnts* pnts);
 
-// bam_fetch callback function for bam_fetch
-static int collectRegionData(const bam1_t *hit, void *data);
+// bam_fetch callback function for bam_fetch for data retrieval from BAM files produced by QuasR and Bismark
+static int collectRegionData_QsBism(const bam1_t *hit, void *data);
+
+// bam_fetch callback function for bam_fetch for data retrieval from BAM files produced by BISQUIT
+static int collectRegionData_Bisq(const bam1_t *hit, void *data);
+
+
 
 // checks validity of an alignment
 bool isValidAln(const bam1_t *hit,const obj_pnts* pdata);
diff --git a/src/functions_export_rcpp.cpp b/src/functions_export_rcpp.cpp
index 8f6c5c5..4b6348c 100644
--- a/src/functions_export_rcpp.cpp
+++ b/src/functions_export_rcpp.cpp
@@ -16,7 +16,8 @@ Rcpp::List fetch_data_matrix_from_bams_cpp(const Rcpp::CharacterVector& whichCon
                                            const Rcpp::NumericVector& max_bisC_meth,
                                            const Rcpp::IntegerVector& min_bisC_size,
                                            const Rcpp::IntegerVector& mapqMin,
-                                           const Rcpp::IntegerVector& mapqMax){
+                                           const Rcpp::IntegerVector& mapqMax,
+                                           const Rcpp::CharacterVector& alignerUsed){
   
   // convert input parameters
   string whichContext_ = Rcpp::as<string>(whichContext);
@@ -34,6 +35,18 @@ Rcpp::List fetch_data_matrix_from_bams_cpp(const Rcpp::CharacterVector& whichCon
   else
     Rcpp::stop("whichContext must be GCH, WCG, bisC, otherC or allC");
   
+  string alignerUsed_ = Rcpp::as<string>(alignerUsed);
+  alignerType aligner;
+  if(alignerUsed_ == "QuasR")
+    aligner = QuasR;
+  else if(alignerUsed_ == "Bismark")
+    aligner = Bismark;
+  else if(alignerUsed_ == "BISQUIT")
+    aligner = BISQUIT;
+  else
+    Rcpp::stop("Only alignments generated by QuasR, Bismark or BISQUIT can be analyzed\n");
+  
+  
   vector<string > infiles_ = Rcpp::as<vector<string > >(infiles);
   string regionChr_ = Rcpp::as<string >(regionChr);
   int regionStart_ = Rcpp::as<int >(regionStart);
@@ -74,6 +87,7 @@ Rcpp::List fetch_data_matrix_from_bams_cpp(const Rcpp::CharacterVector& whichCon
                         regionChr_,
                         regionStart_,
                         regionEnd_,
+                        aligner,
                         &pnts);
   }
   
diff --git a/src/functions_export_rcpp.h b/src/functions_export_rcpp.h
index 33de338..93418e9 100644
--- a/src/functions_export_rcpp.h
+++ b/src/functions_export_rcpp.h
@@ -41,7 +41,8 @@ Rcpp::List fetch_data_matrix_from_bams_cpp(const Rcpp::CharacterVector& whichCon
                                            const Rcpp::NumericVector& max_bisC_meth,
                                            const Rcpp::IntegerVector& min_bisC_size,
                                            const Rcpp::IntegerVector& mapqMin,
-                                           const Rcpp::IntegerVector& mapqMax);
+                                           const Rcpp::IntegerVector& mapqMax,
+                                           const Rcpp::CharacterVector& alignerUsed);
 
 
 
diff --git a/src/utils_globvars.h b/src/utils_globvars.h
index bd6135b..98ea096 100644
--- a/src/utils_globvars.h
+++ b/src/utils_globvars.h
@@ -19,6 +19,13 @@ enum fragMapType{GCH, WCG, bisC, otherC,
                  allC // this is used only to get data matrix with all Cs
                  };
 
+// enumerator for aligners for which we have function implemented
+enum alignerType{QuasR,
+                 Bismark,
+                 BISQUIT
+};
+
+
 // enumerator for type of mismatches
 enum seekMismType{CtoT,GtoA};