Rinse the paramecia off the filter paper into a flask using embryo medium. Repeat until all the stock is filtered. Refilter the paramecia through fluted circles rinsing with embryo medium until most of the yellow color has disappeared. Collect the paramecia in a clean bottle making sure that the yellow color is gone. Rinse again if necessary.
Some paramecia pass through the fluted filters.
If they are needed for feeding, they can be collected by filtering through the Whatman No. 1 circular filter. However, filtering through a Whatman 1 is very slow.