Abstract: A filtration device includes a holding portion having opposed flexible sides with first and second ends, and a filter having an axis corresponding approximately to an edge of the filter, where the axis is coplanar with a planar surface of the filter. The filter may be arranged between the opposed flexible sides, and the filter may be configured to rotate about the axis such that an angle is formed between the planar surface and one of the opposed flexible sides. The filter may be configured to divide the holding portion into first and second holding parts, where the first holding part and the second holding part may be configured to hold fluid received from the first end of the holding portion and filtrate corresponding to the fluid having passed through the filter, respectively. The filtrate may be configured to exit from an opening at the second end.