diff --git a/Client/Client/MainWindow.xaml.cs b/Client/Client/MainWindow.xaml.cs
index 2d1f39a..9b291b6 100644
--- a/Client/Client/MainWindow.xaml.cs
+++ b/Client/Client/MainWindow.xaml.cs
@@ -166,7 +166,7 @@ namespace Client
             TextboxPatientOrt.Clear();
             TextboxPatientRegion.Clear();
             TextboxPatientGeburtstag.Clear();
-            ComboBoxBakterienstamm.Items.Clear();
+            ComboBoxBakterienstamm.SelectedItem = null; //ItemsControl.ItemsSource
             TextboxNahrung1Restaurant.Clear();
             TextboxNahrung1Essen.Clear();
             TextboxNahrung1Strasse.Clear();