diff --git a/src/scripts/component/selected-chromosome.ts b/src/scripts/component/selected-chromosome.ts
index b9d69b4faa513d3dc288a9f40d52b1887d13105f..8a667a1e576fd27e88407ee941dd25ea5522f387 100644
--- a/src/scripts/component/selected-chromosome.ts
+++ b/src/scripts/component/selected-chromosome.ts
@@ -11,14 +11,14 @@ import { drag } from "d3-drag";
 export default function () {
   const classes = {
     selectedChromosome: "selected-chromosome",
-    rule: "rule",
+    ruler: "chromosome-ruler",
     genes: "genes"
   };
   const ruleComponent = ChromosomeRule();
   const geneComponent = Gene();
 
   function selectedChromosome(
-    _selection: Selection<SVGElement, SelectedChromosomeData[], SVGElement, any>,
+    _selection: Selection<SVGGElement, SelectedChromosomeData[], any, any>,
     width: number
   ) {
     _selection.each(function (_data: SelectedChromosomeData[]) {
@@ -39,7 +39,7 @@ export default function () {
 
       selectedChromosomeEnter
         .append("g")
-        .classed(classes.rule, true);
+        .classed(classes.ruler, true);
 
       selectedChromosomeEnter
         .append("g")
@@ -78,8 +78,8 @@ export default function () {
         );
 
       selectedChromosomeUpdate
-        .select<SVGGElement>("." + classes.rule)
-        .datum<GenericAxisData>(d => d.rule)
+        .select<SVGGElement>("." + classes.ruler)
+        .datum<GenericAxisData>(d => d.ruler)
         .call(ruleComponent, width, 0)
 
       selectedChromosomeUpdate
diff --git a/tests/selected-chromosome.test.ts b/tests/selected-chromosome.test.ts
index f972ad9326d763014f7b1b7101b9a8fd32e807c6..f4bd22b0f3de6fc217f6f2b63ff37b7757fee144 100644
--- a/tests/selected-chromosome.test.ts
+++ b/tests/selected-chromosome.test.ts
@@ -1,8 +1,45 @@
 import SelectedChromosome from "../src/scripts/component/selected-chromosome";
+import { select } from "d3-selection";
+import { SelectedChromosomeData } from "../src/scripts/types";
 
+describe("Test Selected Chromosome", () => {
+  const result = '<g class="selected-chromosome"><rect class="genome-browser-background" width="1500" height="150"></rect><g class="chromosome-ruler" transform="translate(0,0)"><g class="genome-axis"><g class="title"><text style="fill: black; font-family: monospace;" transform="translate(790,20)">Chromosome</text></g><g class="axis-elems" transform="translate(0, 50)" fill="none" font-size="10" font-family="sans-serif" text-anchor="middle"><path class="domain" stroke="currentColor" d="M0.5,-6V0.5H1500.5V-6"></path><g class="tick" opacity="1" transform="translate(79.44736842105263,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">30.0</text></g><g class="tick" opacity="1" transform="translate(237.3421052631579,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">40.0</text></g><g class="tick" opacity="1" transform="translate(395.2368421052631,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">50.0</text></g><g class="tick" opacity="1" transform="translate(553.1315789473684,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">60.0</text></g><g class="tick" opacity="1" transform="translate(711.0263157894736,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">70.0</text></g><g class="tick" opacity="1" transform="translate(868.921052631579,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">80.0</text></g><g class="tick" opacity="1" transform="translate(1026.8157894736842,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">90.0</text></g><g class="tick" opacity="1" transform="translate(1184.7105263157896,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">100</text></g><g class="tick" opacity="1" transform="translate(1342.6052631578948,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">110</text></g><g class="tick" opacity="1" transform="translate(1500.5,0)"><line stroke="currentColor" y2="-6"></line><text fill="currentColor" y="-9" dy="0em">120</text></g></g></g></g><g class="genes"><g class="gene" transform="translate(-236.8421052631579,70)"><path style="fill-opacity: 0.85; stroke-width: 1px; stroke-opacity: 0.8;" transform="translate(0,25) translate(631.578947368421,20) rotate(180)" d="M0,0L0,20L621.578947368421,20L631.578947368421,10L621.578947368421,0Z"></path></g><g class="gene" transform="translate(552.6315789473684,70)"><path style="fill-opacity: 0.85; stroke-width: 1px; stroke-opacity: 0.8;" d="M0,0L0,20L621.5789473684212,20L631.5789473684212,10L621.5789473684212,0Z"></path></g></g></g>'
+  const selectedChromosomeComponent = SelectedChromosome();
+  const window: [number, number] = [25, 120];
+  const data: SelectedChromosomeData[] = [
+    {
+      window,
+      genes: [{
+        name: "gene 1",
+        strand: "-",
+        begin: 10,
+        end: 50,
+        gene: "insA",
+      },
+      {
+        name: "gene 2",
+        strand: "+",
+        begin: 60,
+        end: 100,
+        gene: "yaaY",
+      }],
+      ruler: {
+        title: "Chromosome",
+        interval: window
+      }
+    }
+  ];
+  document.body.innerHTML =
+    '<div><svg width="500"><g id="container"></g></svg></div>';
+  const container = select("svg")
+    .select<SVGGElement>("g");
 
+  container
+    .datum<SelectedChromosomeData[]>(data)
+    .call(selectedChromosomeComponent, 1500);
 
-describe("Test Genome Browser", () => {
-  const selectedChromosomeComponent = SelectedChromosome();
-  test("", () => { })
+  // Start tests
+  test("Test data to DOM elements", () => {
+    expect(container.html()).toBe(result);
+  })
 })
\ No newline at end of file