diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 196c206f..ba66840a 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -2,6 +2,10 @@
 (preview packages available on nuget)
 
 **Additions:**
+
+ * **BioFSharp**:
+   * [Conversion extensions for BioCollections]()
+
  * **BioFSharp.BioContainers**
    * BLAST biocontainer :
      * full blastn, blastn-short, megablast, and dc-megablast DSLs
diff --git a/src/BioFSharp/BioCollectionsExtensions.fs b/src/BioFSharp/BioCollectionsExtensions.fs
new file mode 100644
index 00000000..16bd939b
--- /dev/null
+++ b/src/BioFSharp/BioCollectionsExtensions.fs
@@ -0,0 +1,43 @@
+namespace BioFSharp
+
+open BioSeq
+open BioArray
+open BioList
+
+[<AutoOpen>]
+module BioCollectionsExtensions = 
+    module BioSeq =
+    
+        [<CompiledName("ToBioArray")>]
+        let toBioArray  (bioSeq:BioSeq<_>) : BioArray<_> = Seq.toArray bioSeq    
+        [<CompiledName("ToBioList")>]
+        let toBioList   (bioSeq:BioSeq<_>) : BioList<_>  = Seq.toList  bioSeq
+
+        [<CompiledName("OfBioArray")>]
+        let ofBioArray  (bioArray:BioArray<_>) : BioSeq<_> = Seq.ofArray bioArray
+        [<CompiledName("OfBioList")>]
+        let ofBioList   (bioList :BioList<_>)  : BioSeq<_> = Seq.ofList  bioList
+
+    module BioList =
+    
+        [<CompiledName("ToBioArray")>]
+        let toBioArray  (bioList:BioList<_>) : BioArray<_> = List.toArray bioList
+        [<CompiledName("ToBioSeq")>]
+        let toBioSeq    (bioList:BioList<_>) : BioSeq<_>   = List.toSeq   bioList
+        
+        [<CompiledName("OfBioArray")>]
+        let ofBioArray  (bioArray:BioArray<_>) : BioList<_> = List.ofArray bioArray                                     
+        [<CompiledName("OfBioSeq")>]
+        let ofBioSeq    (bioSeq:BioSeq<_>)     : BioList<_> = List.ofSeq   bioSeq
+
+    module BioArray =
+    
+        [<CompiledName("ToBioList")>]
+        let toBioList   (bioArray:BioArray<_>) : BioList<_> = Array.toList bioArray
+        [<CompiledName("ToBioSeq")>]
+        let toBioSeq    (bioArray:BioArray<_>) : BioSeq<_>  = Array.toSeq  bioArray
+
+        [<CompiledName("OfBioList")>]
+        let ofBioList   (bioList :BioList<_>)  : BioArray<_> = Array.ofList  bioList
+        [<CompiledName("OfBioSeq")>]                    
+        let ofBioSeq    (bioSeq  :BioSeq<_>)   : BioArray<_> = Array.ofSeq   bioSeq
\ No newline at end of file
diff --git a/src/BioFSharp/BioFSharp.fsproj b/src/BioFSharp/BioFSharp.fsproj
index fbb21ff5..11f26e48 100644
--- a/src/BioFSharp/BioFSharp.fsproj
+++ b/src/BioFSharp/BioFSharp.fsproj
@@ -44,6 +44,7 @@
     <Compile Include="BioSeq.fs" />
     <Compile Include="BioArray.fs" />
     <Compile Include="BioList.fs" />
+    <Compile Include="BioCollectionsExtensions.fs" />
     <Compile Include="AminoProperties.fs" />
     <Compile Include="IsoelectricPoint.fs" />
     <Compile Include="Digestion.fs" />
@@ -75,6 +76,7 @@
     <None Include="Playground\BioItemsConverter.fsx" />
     <None Include="Playground\BioList.fsx" />
     <None Include="Playground\BioSeq.fsx" />
+    <None Include="Playground\BioCollectionsExtensions.fsx" />
     <None Include="Playground\Digestion.fsx" />
     <None Include="Playground\Elements.fsx" />
     <None Include="Playground\Formula.fsx" />
diff --git a/src/BioFSharp/Playground/BioCollectionsExtensions.fsx b/src/BioFSharp/Playground/BioCollectionsExtensions.fsx
new file mode 100644
index 00000000..b00d81d0
--- /dev/null
+++ b/src/BioFSharp/Playground/BioCollectionsExtensions.fsx
@@ -0,0 +1,53 @@
+#r "../../../packages/FSharpAux/lib/netstandard2.0/FSharpAux.dll"
+
+#load "../PhysicalConstants.fs"
+#load "../BioID.fs"
+#load "../Isotopes.fs"
+#load "../Elements.fs"
+#load "../Formula.fs"
+#load "../Mass.fs"
+#load "../IBioItem.fs"
+#load "../TaggedSequence.fs"
+#load "../IsotopicDistribution.fs"
+#load "../ModificationInfo.fs"
+#load "../AminoAcidSymbols.fs"
+#load "../AminoAcids.fs"
+#load "../Nucleotides.fs"
+#load "../GlobalModificationInfo.fs"
+#load "../BioItemsConverter.fs"
+#load "../BioSeq.fs"
+#load "../BioArray.fs"
+#load "../BioList.fs"
+#load "../BioCollectionsExtensions.fs"
+
+open BioFSharp
+
+let testSeq =
+    BioSeq.ofAminoAcidString "TESTESTESTLUL"
+
+testSeq |> BioSeq.toString
+
+let meem = 
+
+    testSeq
+
+    |> BioList.ofBioSeq
+    |> BioSeq.toBioList
+
+    |> BioArray.ofBioList
+    |> BioArray.toBioList
+
+    |> BioSeq.ofBioList
+    |> BioSeq.toBioArray
+
+    |> BioList.ofBioArray
+    |> BioList.toBioArray
+
+    |> BioSeq.ofBioArray
+    |> BioSeq.toBioList
+
+    |> BioList.toBioSeq
+    |> BioArray.ofBioSeq
+    |> BioArray.toBioSeq
+
+(BioSeq.isEqual testSeq meem ) = 0
\ No newline at end of file