A tissue separating device and a method of separating pure fat from a fatty liposuction aspirate are provided. The tissue separating device includes a canister device including canister body having a sidewall defining a volume. A tissue retrieval port can be arranged on the canister device and is capable of being arranged in fluid communication with a harvesting device for directing a fatty liposuction aspirate into the volume of the canister device. An adjustable height filtration mesh assembly can be arranged within the canister body and can include a filtering mesh separating the volume into an upper vacuum chamber and a lower vacuum chamber. A tissue harvesting port can be arranged in the sidewall of the canister body and can be capable of being arranged in communication with a collection device to allow the tissue harvesting port to atraumatically receive a filtered pure fat collected on the filtering mesh within the upper vacuum chamber. The filtration mesh assembly can be movably arranged within the canister body such that the filtering mesh is adjustable with respect to the tissue harvesting port.