Our Human AB Serum is collected from healthy male donors with an AB blood type. A single gendered pool is generally used to reduce variation in the final product. Furthermore, The AB male blood type raw material, because of lacking A and B antibodies, guarantees that the serum will not react with other blood types, minimizes immunoreactivity and reduces the batch-to-batch variation caused by mix-gender blood collection. Human AB Serum is manufactured exploiting two different methods: plasma-derived and off-the-clot. -Plasma-derived Human AB Serum is manufactured using donor source plasma which is converted into serum by the chemical defibrination process. Bovine or human thrombin is used as the defibrinating agent, turning plasma into serum. -Off-the-clot Human AB Serum is produced from donor whole blood without using anticoagulant, wherein the blood is allowed to clot naturally, and the serum is extracted from the resultant fractionation. This process results in a product with higher amount of retaining of various growth factors found in whole blood without additional processing compounds, making it the closest thing to normal human material. Noteworthy, the off-the-clot serum is produced with more donors per batch, making it a more challenging product to produce.