diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/sample/LibrarySampleBatchRegistrationForm.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/sample/LibrarySampleBatchRegistrationForm.java
index 07411617721977495fd0f2d0dbfde8da7a064626..5e38c4b8ab76241ddd16aede617010dedf8b2d80 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/sample/LibrarySampleBatchRegistrationForm.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/sample/LibrarySampleBatchRegistrationForm.java
@@ -64,6 +64,13 @@ public final class LibrarySampleBatchRegistrationForm extends AbstractSampleBatc
         {
             return character;
         }
+
+        // toString is used in combo box for String representation
+        @Override
+        public String toString()
+        {
+            return name() + " (" + character + ")";
+        }
     }
 
     private static final String PLATES = "Plates";
@@ -150,7 +157,7 @@ public final class LibrarySampleBatchRegistrationForm extends AbstractSampleBatc
         options.setForceSelection(true);
         options.setEditable(false);
         options.setAllowBlank(false);
-        options.setSimpleValue(Separator.COMMA); // TODO TAB? display settings?
+        options.setSimpleValue(Separator.COMMA);
         FieldUtil.markAsMandatory(options);
         return options;
     }