Attachment of primary cell cultures

[Fengling Chen]

In a paper published in 1990, it was suggested that culture flasks be
coated with Poly-D-Lysine to aid in cell attachment to the culture flask
surface.  I am currently using petri dishes specially designed for cell
cultures, and am wondering if it is still necessary to coat the petri
dishes with the Poly-D-Lysine when establishing a primary cell culture. 
Are the petri dishes already coated with poly-d-Lysine or must I coat them
myself or need they be coated at all?

Thanks
Fengling Chen