Photoelectric methods of measuring the velocity of rapid reactions - III—A portable micro-apparatus applicable to an extended range of reactions

Abstract

This paper describes the portable, micro form of the kinetic apparatus which has been under continuous development and use in this laboratory during the past six years. It differs from the simpler form described in the preceding paper in being capable of dealing with much smaller quantities of reactants, with more rapid reactions, and with a wider selection of coloured substances, whose kinetics can be studied over a larger concentration range. While specifically designed for the study of blood pigments of small and valuable animals, where sometimes only 1 or 2 cc of material is available, the technique is equally applicable to any pigment reaction, either in the presence of air or under strictly anaerobic conditions. The method has been used for a number of different investigations on haemoglobins, muscle haemoglobin, haemocyanines, melanin, ascorbic acid (with Tillman’s reagent), and reactions involving p h changes (with indicators). In the course of these studies, the technique and apparatus have gradually assumed their present fairly definitive form, and the procedure has become considerably simplified. The device has also been brought into a compact, portable form, so that it may easily be carried in a car or train to the source of supply of perishable biological substances, or to a constant temperature room. It was in fact transported in the author’s car from Cambridge to Berlin in June, 1934, and was used for investigations at the Kaiser Wilhelm Institut für Zellphysiologie during that summer.