The present invention pertains to the field of
medicine and relates to a bag used for the collection, storage and separation of blood derivatives. The present patent is designed to enable the collection and separation of blood components in a single bag, suitable for generating fractionated bags and blood sample aliquots. This practice eliminates the risk of
contamination due to the transfer and / or
exposure of the blood products. The invention relates to a bag (1) composed of two superimposed polymeric films (2) and (3) sealed along their perimeter, and provided at its two ends with connectors (4), (5), (6), and (7), and handles (8) and (9), respectively; the bag (1) comprises an
hourglass-shaped narrowing (10), formed by two trapezoidal seams (11) and (12) arranged opposite each other; the narrowing (10) has a length of between 6 mm and 15 mm (preferably 10 cm), a width of between 2 cm and 6 cm (preferably 4 cm), and angles (α), (β), (γ), and (δ) of between 10° and 60° (preferably 20°), while two or more demarcation lines (13) and (14) are placed transversely on both faces, on the narrowed region (11).