Keratin is a hair and skin protein which occurs almost everywhere in dust. It can easily contaminate lab equipment and reaction tubes because of electrostatic charging.
We therefore recommend using only RNase-free reaction tubes and pipetting tips. Tubes and lab dishes used for staining etc. should be well rinsed with 0.2 µm filtered Milli-Q water before use and kept covered during usage. Also it is highly recommendable to use a laminar flow clean bench to prevent direct contamination of protein gels by dust and skin particles. If not available wipe your near working environment with a wet cloth.
Make sure not to use staining dishes that were previously used for immunologic blocking with BSA, milk powder or other protein solutions.
Please note that autoclavation does not eliminate Keratin.