A tissue collection apparatus maximizes the collection and retention of tissue samples from within a patient. The apparatus comprises a handle with a hollow catheter flexibly extending distally from the handle. A cytology brush is stored within the hollow at a distal end of the cannula, and can be extended and retracted from the cannula by manipulating the handle. The cytology brush has a cylindrical proximal brush, a cylindrical distal brush, and a tissue collection gap longitudinally separating the proximal and distal brushes. The bristles of the brushes can have different material properties and can have an effective diameter greater than the cannula. In use, tissue samples accumulate within the bristles and within the tissue collection gap. When retracted into the hollow of the cannula, the apparatus maximizes the amount of tissue collected by folding the bristles over the tissue collection gap to shield the tissue samples collected within.