Specificity of antisera produced against mitomycin C.

The specificity of antisera produced in rabbits for use in mitomycin C (MMC) enzyme immunoassay has been examined employing competitive experiments using several mitomycin analogs and the chemically or biologically degraded preparations of MMC. These studies demonstrate that the antiserum distinguished alterations in the chemical structure of the molecule, showing decreased immunoreactivity with mitomycin A (7.8%) and B (0.78%). On the other hand, porfiromycin and acetyl MMC (Ac-MMC), which commonly possess the substituted groups (methyl and acetyl groups, respectively) at the aziridine ring, showed enhanced reactivity with the antiserum (about two times and ten times as compared to the parent MMC, respectively), suggesting that the antigen used for antibody production was the MMC acylated at the imino group of the aziridine ring. The values of the chemically or biologically degraded preparations of MMC quantified by this enzyme immunoassay were in good agreement with those of the remaining nonreacted MMC measured spectrophotometrically, thus indicating that the anti-MMC antiserum hardly cross-reacted with these degradation products.