COMPARATIVE STUDIES ON THE METHODS FOR PREPARING SERUM

Abstract

There are, as is known, several methods for preparing serum to be used for therapeutic and diagnostic purposes, but the clotting process and the defibrination followed by centrifugation have widely been employed with noticeable efficiency in practical work. While by the former method clear and sterile serum is obtainable, simply allowing the blood to clot, the latter gives higher percentages in the gain of serum. It often occurs, however, by employing the latter method that the material is accidentally contaminated during the process of centrifugation and the serum obtained becomes quite unfit for use. In order to prevent the accidental contamination and to obtain a large possible amount of sterile seerum, several kinds of apparatus have atreacly been designed. As it will be of great interest to know which is the best method, which is the best apparatus and in what condition the serum gain is largest, I have made some experiments, employing the known methods and apparatuses, to determine, as a first step, the relation between the yield of serum and the amount of bleeding, slight starvation, atmospheric pressure, temperature, size and shape of glass jar, etc. The apparatuses used in my experiments are:1) The apparatus used in the Pasteur Institute, Paris.2) The bucket for blood clotting designed by the Laboratory of the Indian Civil Veterinary Department.3) Latapie's apparatus.The results obtained are as follows:1) The yield of serum depends upon the individuality of animals and the total sum of the serum which is obtained from the usual clot at 2-day-intervals during 9 days amounts to 41-64% of the whole blood drawn.2) The percentage of serum from the first bleeding (4000c.c.) was lower by 6.5% than that from the second which, being same in the quantity of blood, took place 2 days later.No influence of an atmospheric pressure and slight starvation upon the yield of serum has been observed.4) The adequate temperature for separation of serum is about 20°C.5) The amount of serum obtained is proportional to the height of glass jar.6) The compressive method employed in the Veterinary Laboratory at Buitenzorg (Java) is most applicable in horse and swine blood. According to the experiments, this method requires no complicated apparatus, shortens the time necessary for collec-ting serum, gives serum 4-13% more than that obtained from the usual clot, and the serum is guite free from hemoglobin. As for the bucket of Indian Civil Veterinary Laboratory, it seems to be more favourable to use it for the preparation of serum from cattle blood, though the serum is often found in an impure state, slightly mixed with red blood corpuscles.