Biochemical Journal92(3),614–621(1964), DOI10.1042/bj0920614. Primary PDF portlandpress.com/biochemj/article-pdf/92/3/614/702742/bj0920614.pdf ; author-hosted scan www.chris-anthony.co.uk/pdf_files/AnthonyCOMPLETE/Papers/MDH/Ant%26%20Zat64b.pdf . Indexed original p.614 describes Unicam SP.500/10mm cuvettes; p.620/Table2 separates reaction mixture by steam distillation before formaldehyde assay and explicitly cautions that free versus bound formaldehyde is unresolved. Published initials retained.
Additional verified locator: p.614, Materials and Methods, describes the optical apparatus and DCPIP standardization at600nm for the carrier-coupled assay.