diff --git a/src/1_JU28_59vs17_SNP_calling.sh b/src/1_JU28_59vs17_SNP_calling.sh
index 5937da14f2e2884dd3ab9789abc23698eca3bb73..be184a5d28a761426da572ccad00f2a05a7b6634 100644
--- a/src/1_JU28_59vs17_SNP_calling.sh
+++ b/src/1_JU28_59vs17_SNP_calling.sh
@@ -11,7 +11,7 @@ cd ~/projects/JU28_59vs17_SNP/
 
 # training set analysis
 
-./nextflow src/SNP_calling.nf -c src/SNP_calling.config -profile docker --fasta "data/fasta/DBG2OLC-output2.fasta" --fastq "data/samples/*_{1,2}.fastq.gz" -resume -w ~/data/work/ --tumor "[\"NG-10944_JU2859_bis_lib169352_5217_1\"]" --normal "[\"MR_550_clean\", \"MR_350_clean\"]"
+./nextflow src/SNP_calling.nf -c src/SNP_calling.config -profile docker --fasta "data/fasta/DBG2OLC-output2.fasta" --fastq "data/samples/*_{1,2}.fastq.gz" -resume -w ~/data/work_s/ --tumor "[\"s_NG-10944_JU2859_bis_lib169352_5217_1\"]" --normal "[\"s_MR_550_clean\", \"s_MR_350_clean\"]"
 ~/scripts/sms.sh "SNP done"
 
 # real set analysis
diff --git a/src/SNP_calling.config b/src/SNP_calling.config
index 4b693893951517f76dd13ab6bc51448a8575c488..24d288442ac8b9c32b4b06bdca044a2bf80623d5 100644
--- a/src/SNP_calling.config
+++ b/src/SNP_calling.config
@@ -10,10 +10,10 @@ profiles {
         container = "urqt:d62c1f8"
       }
       withName: index_fasta {
-        container = "bwa:0.7.17"
+        container = "bowtie2:2.3.4.1"
       }
       withName: mapping_fastq {
-        container = "bwa:0.7.17"
+        container = "bowtie2:2.3.4.1"
       }
       withName: merge_bam {
         container = "sambamba:0.6.7"
@@ -21,9 +21,6 @@ profiles {
       withName: sort_bam {
         container = "sambamba:0.6.7"
       }
-      withName: name_fasta {
-        container = "samtools:1.7"
-      }
       withName: index_bam {
         container = "sambamba:0.6.7"
       }
diff --git a/src/SNP_calling.nf b/src/SNP_calling.nf
index 56f0568b08dda9aa69343b7c98a2dc170bcf5f1a..3d040bfced133f1ef6c794a20e4e805e369d3604 100644
--- a/src/SNP_calling.nf
+++ b/src/SNP_calling.nf
@@ -62,62 +62,56 @@ UrQt --t 20 --m ${task.cpus} --gz \
 }
 
 process index_fasta {
-  tag "$fasta_id"
+  tag "$file_id"
   cpus 4
   publishDir "results/mapping/index/", mode: 'copy'
 
   input:
-    set fasta_id, file(fasta) from fasta_file
+    set file_id, file(fasta) from fasta_file
 
   output:
-    set fasta_id, "${fasta.baseName}.*" into index_files
-    file "*_bwa_report.txt" into index_files_report
+    file "*.index*" into index_files
+    file "*_report.txt" into indexing_report
 
   script:
 """
-bwa index -p ${fasta_id} ${fasta} \
-&> ${fasta.baseName}_bwa_report.txt
-"""
-}
-
+bowtie2-build --threads ${task.cpus} ${fasta} ${file_id}.index &> ${file_id}_bowtie2_report.txt
 
-fastq_files_trim.into {
-  fastq_files_trim_norm;
-  fastq_files_trim_tumor
+if grep -q "Error" ${file_id}_bowtie2_report.txt; then
+  exit 1
+fi
+"""
 }
 
-collect_fastq_files_trim_norm = fastq_files_trim_norm
-  .filter{ normal_sample.contains(it[0]) }
-  .map { it -> ["normal_sample", it[0], it[1]]}
-
-collect_fastq_files_trim_tumor = fastq_files_trim_tumor
-  .filter{ tumor_sample.contains(it[0]) }
-  .map { it -> ["tumor_sample", it[0], it[1]]}
-
-collect_fastq_files_trim = Channel.create()
-  .mix(collect_fastq_files_trim_norm, collect_fastq_files_trim_tumor)
-
 process mapping_fastq {
   tag "$pair_id"
-  cpus 6
-  publishDir "results/mapping/bam/", mode: 'copy'
+  cpus 4
+  publishDir "results/mapping/bams/", mode: 'copy'
 
   input:
-  set sample_name, pair_id, file(reads) from collect_fastq_files_trim
-  set index_id, file(index) from index_files.collect()
+  set pair_id, file(reads) from fastq_files_trim
+  file index from index_files.collect()
 
   output:
-  set pair_id, "${pair_id}.bam" into bam_files
-  file "${pair_id}_bwa_report.txt" into mapping_repport_files
+  set pair_id, "*.bam" into bam_files
+  file "*_report.txt" into mapping_report
 
   script:
+  index_id = index[0]
+  for (index_file in index) {
+    if (index_file =~ /.*\.1\.bt2/ && !(index_file =~ /.*\.rev\.1\.bt2/)) {
+        index_id = ( index_file =~ /(.*)\.1\.bt2/)[0][1]
+    }
+  }
 """
-bwa mem -t ${task.cpus} -M \
--R '@RG\\tID:${sample_name}\\tSM:${sample_name}\\tPL:Illumina' \
-${index_id} ${reads[0]} ${reads[1]} | \
-samblaster --addMateTags -M -i /dev/stdin | \
-sambamba view -t ${task.cpus} --valid -S -f bam -l 0 /dev/stdin -o ${pair_id}.bam \
-2> ${pair_id}_bwa_report.txt
+bowtie2 --very-sensitive -p ${task.cpus} -x ${index_id} \
+-1 ${reads[0]} -2 ${reads[1]} 2> \
+${pair_id}_bowtie2_report.txt | \
+samtools view -Sb - > ${pair_id}.bam
+
+if grep -q "Error" ${pair_id}_bowtie2_report.txt; then
+  exit 1
+fi
 """
 }
 
@@ -192,7 +186,7 @@ process index_bam {
     set file_id, file(bam) from index_merged_bam_files
 
   output:
-    set file_id, "*.bam*" into index_bam_files
+    set file_id, "*.bam.bai" into index_bam_files
 
   script:
 """