Problem while storing data in Datacolumn

Hi,

I have created data table and added columns to it. One thing i have observed that for string data it is storing only 200 byets of data. if data is more than 200 bytes it gets truncated.

dtRefIndices = new DataTable();

dtRefIndices.Columns.Add("INDEX_CODE");
dtRefIndices.Columns.Add("INDEX_SYMBOL");

I want to store more than 200 bytes of data.
Need u'r help.

Parag