maybe the problem is due to the hydrophobic nature of the plates.
Pierce carries hydrophilic plates, Prod 15100, but they are not
sterile. I don't know that any other company has sterile plates.
Alternatively you can try coating with a product such as Aquasil
(also Pierce) which is a siliconizing fluid used on glass to
make glass water repellent and less likely to absorb proteins etc.
IT IS JUST A THOUGHT - I have no hands on experience.
