The validity of the microchemical test for the oxygen place in tissues

Abstract

In the last few years endeavours have been made to locate precisely certain reaction known to occur in the living cell; and much work has been done especially on the reduction place, the oxygen place, and the position of oxidases and peroxidases. The reaction relied upon to indicate the position is always one involving a colour change ; as an example, Unna’s method of fixing the oxygen place in the cell may be chosen. He uses for this purpose a solution of Rongalit white, which is a solution of the leucobase of methylene blue kept in a state of reduction by excess of rongalit, an adsorption product of formaldehyde with white sodium sulphite. This solution is not affected by air or by light, but is, according to Unna, a test for active oxygen. He places the section in a solution of rongalit white for one minute, then washes in a large volume of water; when the reducer having been washed away, the tissue is able to shoe its ability to oxidise, and all the tissue elements which are capable of effecting an oxidation are blued owing to the oxidation of the methylene white to methylene blue.