FIELD : medicine; pharmaceuticals.SUBSTANCE : group of inventions relates to the pharmaceutical industry, specifically to a method of producing an isolated fraction of serum from platelet-rich fibrin (PRF). Method for producing the separated PRF serum fraction containing the following steps : providing thrombocyte-enriched plasma (TEP) from a venous blood sample without adding an anticoagulant; coagulation of plasma in order to obtain PRF coagel by centrifugation in order to obtain coagel and separation of coagel by pressing, squeezing, filtering and/or centrifuging of said coagel with separation of a serum fraction containing a liquid fraction of TEP, which contains an activated agent of activated thrombocytes, where TEP spontaneously coagulates when it is obtained by centrifuging a blood sample, wherein said coagulation is accelerated by contact with negatively charged surfaces and without adding exogenous coagulation activators under certain conditions. Selected whey fraction. Application of whey fraction. Pharmaceutical preparation for medical use for tissue regeneration. Kit for medical application for tissue regeneration. Method for stimulating cell proliferation.EFFECT : above-described group of solutions enables accelerating cell proliferation, repair and tissue healing, particularly in osteoarthritis material and bone tissue after ischemic bone injury.29 cl, 5 dwg, 1 tbl, 7 ex