diff --git a/SystemExtensions/Collections/AVLTree.cs b/SystemExtensions/Collections/AVLTree.cs
index 7c8f127..638095c 100644
--- a/SystemExtensions/Collections/AVLTree.cs
+++ b/SystemExtensions/Collections/AVLTree.cs
@@ -13,15 +13,17 @@ namespace SystemExtensions.Collections
     /// Read on https://simpledevcode.wordpress.com/2014/09/16/avl-tree-in-c/
     /// </summary>
     /// <typeparam name="T">Provided type.</typeparam>
+    [Serializable]
     public class AVLTree<T> : ICollection<T> where T : IComparable<T>
     {
         #region Fields
-        private class AVLNode<T>
+        [Serializable]
+        private class AVLNode<TKey>
         {
-            public T Value;
-            public AVLNode<T> Left;
-            public AVLNode<T> Right;
-            public AVLNode(T value)
+            public TKey Value;
+            public AVLNode<TKey> Left;
+            public AVLNode<TKey> Right;
+            public AVLNode(TKey value)
             {
                 this.Value = value;
             }
diff --git a/SystemExtensions/Collections/BinaryHeap.cs b/SystemExtensions/Collections/BinaryHeap.cs
index 415c821..6af65aa 100644
--- a/SystemExtensions/Collections/BinaryHeap.cs
+++ b/SystemExtensions/Collections/BinaryHeap.cs
@@ -11,6 +11,7 @@ namespace SystemExtensions.Collections
     /// Binary heap implementation.
     /// </summary>
     /// <typeparam name="T">Provided type.</typeparam>
+    [Serializable]
     public class BinaryHeap<T> : IEnumerable<T> where T : IComparable<T>
     {
         #region Fields
diff --git a/SystemExtensions/Collections/FibonacciHeap.cs b/SystemExtensions/Collections/FibonacciHeap.cs
index 75a606e..f97f2cd 100644
--- a/SystemExtensions/Collections/FibonacciHeap.cs
+++ b/SystemExtensions/Collections/FibonacciHeap.cs
@@ -11,6 +11,7 @@ namespace SystemExtensions.Collections
     /// Fibonacci Heap implementation.
     /// </summary>
     /// <typeparam name="T">Provided type</typeparam>
+    [Serializable]
     public class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
     {
         #region Fields
@@ -460,7 +461,7 @@ namespace SystemExtensions.Collections
         }
         #endregion
     }
-
+    [Serializable]
     internal class FibonacciNode<T>
     {
         #region Fields
diff --git a/SystemExtensions/Collections/PriorityQueue.cs b/SystemExtensions/Collections/PriorityQueue.cs
index c3a54df..f128fab 100644
--- a/SystemExtensions/Collections/PriorityQueue.cs
+++ b/SystemExtensions/Collections/PriorityQueue.cs
@@ -12,6 +12,7 @@ namespace SystemExtensions.Collections
     /// Exposes some of the functionality of the Binary Heap as a queue.
     /// </summary>
     /// <typeparam name="T">Provided type.</typeparam>
+    [Serializable]
     public class PriorityQueue<T> : IQueue<T> where T : IComparable<T>
     {
         #region Fields
diff --git a/SystemExtensions/Collections/SkipList.cs b/SystemExtensions/Collections/SkipList.cs
index aa970e0..66963cd 100644
--- a/SystemExtensions/Collections/SkipList.cs
+++ b/SystemExtensions/Collections/SkipList.cs
@@ -11,9 +11,11 @@ namespace SystemExtensions.Collections
     /// Skip list implementation.
     /// </summary>
     /// <typeparam name="T">Provided type.</typeparam>
+    [Serializable]
     public class SkipList<T> : ICollection<T> where T : IComparable<T>
     {
         #region Fields
+        [Serializable]
         private class NodeSet<TKey>
         {
             public TKey Key;
diff --git a/SystemExtensions/Collections/Treap.cs b/SystemExtensions/Collections/Treap.cs
index 059c262..3615634 100644
--- a/SystemExtensions/Collections/Treap.cs
+++ b/SystemExtensions/Collections/Treap.cs
@@ -11,15 +11,17 @@ namespace SystemExtensions.Collections
     /// Treap implementation.
     /// </summary>
     /// <typeparam name="T">Provided type.</typeparam>
+    [Serializable]
     public class Treap<T> : ICollection<T> where T : IComparable<T>
     {
         #region Fields
-        private class Item<T>
+        [Serializable]
+        private class Node<TKey>
         {
-            public T Key;
+            public TKey Key;
             public int Priority;
-            public Item<T> Left, Right;
-            public Item(T key, int priority)
+            public Node<TKey> Left, Right;
+            public Node(TKey key, int priority)
             {
                 Key = key;
                 Priority = priority;
@@ -28,7 +30,7 @@ namespace SystemExtensions.Collections
             }
         }
         private Random randomGen;
-        private Item<T> root;
+        private Node<T> root;
         private int count;
         #endregion
         #region Properties
@@ -130,10 +132,10 @@ namespace SystemExtensions.Collections
         }
         #endregion
         #region Private Methods
-        private Item<T> InsertNode(Item<T> node, T key)
+        private Node<T> InsertNode(Node<T> node, T key)
         {
             if(node == null) {
-                node = new Item<T>(key, randomGen.Next(0, 100));
+                node = new Node<T>(key, randomGen.Next(0, 100));
                 return node;
             }
             else if (key.CompareTo(node.Key) <= 0)
@@ -154,7 +156,7 @@ namespace SystemExtensions.Collections
             }
             return node;
         }
-        private Item<T> RemoveNode(Item<T> node, T key)
+        private Node<T> RemoveNode(Node<T> node, T key)
         {
             if(node == null)
             {
@@ -188,21 +190,21 @@ namespace SystemExtensions.Collections
             }
             return node;
         }
-        private Item<T> RotateRight(Item<T> node)
+        private Node<T> RotateRight(Node<T> node)
         {
-            Item<T> temp = node.Left, temp2 = temp.Right;
+            Node<T> temp = node.Left, temp2 = temp.Right;
             temp.Right = node;
             node.Left = temp2;
             return temp;
         }
-        private Item<T> RotateLeft(Item<T> node)
+        private Node<T> RotateLeft(Node<T> node)
         {
-            Item<T> temp = node.Right, temp2 = temp.Left;
+            Node<T> temp = node.Right, temp2 = temp.Left;
             temp.Left = node;
             node.Right = temp2;
             return temp;
         }
-        private void Clear(Item<T> node)
+        private void Clear(Node<T> node)
         {
             if(node.Left != null)
             {
@@ -214,7 +216,7 @@ namespace SystemExtensions.Collections
             }
             node.Left = node.Right = null;
         }
-        private Item<T> Find(Item<T> node, T key)
+        private Node<T> Find(Node<T> node, T key)
         {
             if(node == null)
             {
@@ -224,7 +226,7 @@ namespace SystemExtensions.Collections
             {
                 if(node.Key.CompareTo(key) < 0)
                 {
-                    Item<T> found = Find(node.Left, key);
+                    Node<T> found = Find(node.Left, key);
                     if(found == null)
                     {
                         found = Find(node.Right, key);
@@ -233,7 +235,7 @@ namespace SystemExtensions.Collections
                 }
                 else if(node.Key.CompareTo(key) > 0)
                 {
-                    Item<T> found = Find(node.Right, key);
+                    Node<T> found = Find(node.Right, key);
                     if (found == null)
                     {
                         found = Find(node.Left, key);
@@ -246,7 +248,7 @@ namespace SystemExtensions.Collections
                 }
             }
         }
-        private void ToArray(Item<T> node, ref T[] array, ref int index)
+        private void ToArray(Node<T> node, ref T[] array, ref int index)
         {
             if(node != null)
             {
@@ -256,9 +258,9 @@ namespace SystemExtensions.Collections
                 ToArray(node.Right, ref array, ref index);
             }
         }
-        private IEnumerator<T> GetEnumerator(Item<T> currentNode)
+        private IEnumerator<T> GetEnumerator(Node<T> currentNode)
         {
-            Queue<Item<T>> queue = new Queue<Item<T>>();
+            Queue<Node<T>> queue = new Queue<Node<T>>();
             queue.Enqueue(currentNode);
             while(queue.Count > 0)
             {
diff --git a/SystemExtensionsTests/Collections/AVLTreeTests.cs b/SystemExtensionsTests/Collections/AVLTreeTests.cs
index b012881..629fd62 100644
--- a/SystemExtensionsTests/Collections/AVLTreeTests.cs
+++ b/SystemExtensionsTests/Collections/AVLTreeTests.cs
@@ -5,6 +5,8 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Runtime.Serialization.Formatters.Binary;
+using System.IO;
 
 namespace SystemExtensions.Collections.Tests
 {
@@ -124,5 +126,35 @@ namespace SystemExtensions.Collections.Tests
 
             int[] array = avlTree.ToArray();
         }
+
+        [TestMethod()]
+        public void Serialize()
+        {
+            AVLTree<int> avlTree2 = new AVLTree<int>();
+            for (int i = 0; i < 100; i++)
+            {
+                avlTree.Add(i);
+            }
+            BinaryFormatter serializer = new BinaryFormatter();
+            string s = string.Empty;
+            using (var stream = new MemoryStream())
+            {
+                serializer.Serialize(stream, avlTree);
+                stream.Position = 0;
+                avlTree2 = (AVLTree<int>)serializer.Deserialize(stream);
+            }
+            IEnumerator<int> avlTreeEnum = avlTree.GetEnumerator();
+            IEnumerator<int> avlTree2Enum = avlTree2.GetEnumerator();
+            
+            for(int i = 0; i < 100; i++)
+            {
+                if(avlTreeEnum.Current != avlTree2Enum.Current)
+                {
+                    Assert.Fail();
+                }
+                avlTreeEnum.MoveNext();
+                avlTree2Enum.MoveNext();
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/SystemExtensionsTests/Collections/BinaryHeapTests.cs b/SystemExtensionsTests/Collections/BinaryHeapTests.cs
index 38b1c59..aae01a3 100644
--- a/SystemExtensionsTests/Collections/BinaryHeapTests.cs
+++ b/SystemExtensionsTests/Collections/BinaryHeapTests.cs
@@ -6,6 +6,9 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using SystemExtensions;
+using System.Runtime.Serialization.Formatters.Binary;
+using System.Xml.Serialization;
+using System.IO;
 
 namespace SystemExtensions.Collections.Tests
 {
@@ -173,5 +176,34 @@ namespace SystemExtensions.Collections.Tests
 
             Assert.Fail();
         }
+
+        [TestMethod()]
+        public void Serialize()
+        {
+            BinaryHeap<int> binaryHeap2 = new BinaryHeap<int>();
+            for (int i = 0; i < 100; i++)
+            {
+                binaryHeap.Insert(i);
+            }
+            BinaryFormatter serializer = new BinaryFormatter();
+            string s = string.Empty;
+            using (var stream = new MemoryStream()) {
+                serializer.Serialize(stream, binaryHeap);
+                stream.Position = 0;
+                binaryHeap2 = (BinaryHeap<int>)serializer.Deserialize(stream);
+            }
+            IEnumerator<int> binaryHeapEnum = binaryHeap.GetEnumerator();
+            IEnumerator<int> binaryHeapEnum2 = binaryHeap2.GetEnumerator();
+
+            for (int i = 0; i < 100; i++)
+            {
+                if (binaryHeapEnum.Current != binaryHeapEnum2.Current)
+                {
+                    Assert.Fail();
+                }
+                binaryHeapEnum.MoveNext();
+                binaryHeapEnum2.MoveNext();
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/SystemExtensionsTests/Collections/FibonacciHeapTests.cs b/SystemExtensionsTests/Collections/FibonacciHeapTests.cs
index a0a0619..8856e44 100644
--- a/SystemExtensionsTests/Collections/FibonacciHeapTests.cs
+++ b/SystemExtensionsTests/Collections/FibonacciHeapTests.cs
@@ -6,6 +6,8 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Threading;
+using System.Runtime.Serialization.Formatters.Binary;
+using System.IO;
 
 namespace SystemExtensions.Collections.Tests
 {
@@ -175,5 +177,35 @@ namespace SystemExtensions.Collections.Tests
 
             Assert.Fail();
         }
+
+        [TestMethod()]
+        public void Serialize()
+        {
+            FibonacciHeap<int> fibonacciHeap2 = new FibonacciHeap<int>();
+            for (int i = 0; i < 100; i++)
+            {
+                fibonacciHeap.Insert(i);
+            }
+            BinaryFormatter serializer = new BinaryFormatter();
+            string s = string.Empty;
+            using (var stream = new MemoryStream())
+            {
+                serializer.Serialize(stream, fibonacciHeap);
+                stream.Position = 0;
+                fibonacciHeap2 = (FibonacciHeap<int>)serializer.Deserialize(stream);
+            }
+            IEnumerator<int> enum1 = fibonacciHeap.GetEnumerator();
+            IEnumerator<int> enum2 = fibonacciHeap2.GetEnumerator();
+
+            for (int i = 0; i < 100; i++)
+            {
+                if (enum1.Current != enum2.Current)
+                {
+                    Assert.Fail();
+                }
+                enum1.MoveNext();
+                enum2.MoveNext();
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/SystemExtensionsTests/Collections/PriorityQueueTests.cs b/SystemExtensionsTests/Collections/PriorityQueueTests.cs
index 4fd420b..0bb55a7 100644
--- a/SystemExtensionsTests/Collections/PriorityQueueTests.cs
+++ b/SystemExtensionsTests/Collections/PriorityQueueTests.cs
@@ -6,6 +6,8 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using SystemExtensions;
+using System.Runtime.Serialization.Formatters.Binary;
+using System.IO;
 
 namespace SystemExtensions.Collections.Tests
 {
@@ -81,5 +83,35 @@ namespace SystemExtensions.Collections.Tests
                 Assert.Fail();
             }
         }
+
+        [TestMethod()]
+        public void Serialize()
+        {
+            PriorityQueue<int> priorityQueue2 = new PriorityQueue<int>();
+            for (int i = 0; i < 100; i++)
+            {
+                priorityQueue.Enqueue(i);
+            }
+            BinaryFormatter serializer = new BinaryFormatter();
+            string s = string.Empty;
+            using (var stream = new MemoryStream())
+            {
+                serializer.Serialize(stream, priorityQueue);
+                stream.Position = 0;
+                priorityQueue2 = (PriorityQueue<int>)serializer.Deserialize(stream);
+            }
+            IEnumerator<int> enum1 = priorityQueue.GetEnumerator();
+            IEnumerator<int> enum2 = priorityQueue2.GetEnumerator();
+
+            for (int i = 0; i < 100; i++)
+            {
+                if (enum1.Current != enum2.Current)
+                {
+                    Assert.Fail();
+                }
+                enum1.MoveNext();
+                enum2.MoveNext();
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/SystemExtensionsTests/Collections/SkipListTests.cs b/SystemExtensionsTests/Collections/SkipListTests.cs
index 7c6c427..4f6511f 100644
--- a/SystemExtensionsTests/Collections/SkipListTests.cs
+++ b/SystemExtensionsTests/Collections/SkipListTests.cs
@@ -5,6 +5,8 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Runtime.Serialization.Formatters.Binary;
+using System.IO;
 
 namespace SystemExtensions.Collections.Tests
 {
@@ -124,5 +126,35 @@ namespace SystemExtensions.Collections.Tests
                 Assert.Fail();
             }
         }
+
+        [TestMethod()]
+        public void Serialize()
+        {
+            SkipList<int> skipList2 = new SkipList<int>();
+            for (int i = 0; i < 100; i++)
+            {
+                skipList.Add(i);
+            }
+            BinaryFormatter serializer = new BinaryFormatter();
+            string s = string.Empty;
+            using (var stream = new MemoryStream())
+            {
+                serializer.Serialize(stream, skipList);
+                stream.Position = 0;
+                skipList2 = (SkipList<int>)serializer.Deserialize(stream);
+            }
+            IEnumerator<int> enum1 = skipList.GetEnumerator();
+            IEnumerator<int> enum2 = skipList2.GetEnumerator();
+
+            for (int i = 0; i < 100; i++)
+            {
+                if (enum1.Current != enum2.Current)
+                {
+                    Assert.Fail();
+                }
+                enum1.MoveNext();
+                enum2.MoveNext();
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/SystemExtensionsTests/Collections/TreapTests.cs b/SystemExtensionsTests/Collections/TreapTests.cs
index 8919ffc..423c64a 100644
--- a/SystemExtensionsTests/Collections/TreapTests.cs
+++ b/SystemExtensionsTests/Collections/TreapTests.cs
@@ -5,6 +5,8 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Runtime.Serialization.Formatters.Binary;
+using System.IO;
 
 namespace SystemExtensions.Collections.Tests
 {
@@ -110,5 +112,35 @@ namespace SystemExtensions.Collections.Tests
 
             Assert.Fail();
         }
+
+        [TestMethod()]
+        public void Serialize()
+        {
+            Treap<int> treap2 = new Treap<int>();
+            for (int i = 0; i < 100; i++)
+            {
+                treap.Add(i);
+            }
+            BinaryFormatter serializer = new BinaryFormatter();
+            string s = string.Empty;
+            using (var stream = new MemoryStream())
+            {
+                serializer.Serialize(stream, treap);
+                stream.Position = 0;
+                treap2 = (Treap<int>)serializer.Deserialize(stream);
+            }
+            IEnumerator<int> enum1 = treap.GetEnumerator();
+            IEnumerator<int> enum2 = treap2.GetEnumerator();
+
+            for (int i = 0; i < 100; i++)
+            {
+                if (enum1.Current != enum2.Current)
+                {
+                    Assert.Fail();
+                }
+                enum1.MoveNext();
+                enum2.MoveNext();
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/SystemExtensionsTests/SystemExtensionsTests.csproj b/SystemExtensionsTests/SystemExtensionsTests.csproj
index be24684..74d98d4 100644
--- a/SystemExtensionsTests/SystemExtensionsTests.csproj
+++ b/SystemExtensionsTests/SystemExtensionsTests.csproj
@@ -46,6 +46,7 @@
       <HintPath>..\packages\MSTest.TestFramework.1.3.2\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.dll</HintPath>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Xml" />
   </ItemGroup>
   <Choose>
     <When Condition="('$(VisualStudioVersion)' == '10.0' or '$(VisualStudioVersion)' == '') and '$(TargetFrameworkVersion)' == 'v3.5'">