Remove check box column from datagridview when clear datagridview using c#

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C#

VB

WPF

DataGridView

DataGrid

i have created datagridview dynamically with check box column,once i refresh my datagrid its removes all data except checkbox column,below code for adding checkbox column in datagrid

DataGridViewCheckBoxColumn chk = new DataGridViewCheckBoxColumn();
dataGridView1.Columns.Add(chk);
chk.HeaderText = "Check Data";
chk.Name = "chk";
 int count = dataGridView1.Rows.Count;
 for (int i = 0; i < count; i++)
 {
     dataGridView1.Rows[i].Cells[12].Value = false;
 }

and below code for clearing my datagrid,if i try to add new data in datagridview after refresh still old check box exists and it keeps adding one more checkbox column.

dataGridView1.Rows.Clear();
dataGridView1.Refresh();

any suggestion???