His undergraduate thesis "Über Kaliumborfluoridtetraschwefeltrioxyd und die Darstellung von Trisulfurylfluorid“ (About potassium borofluoride tetrasulfur trioxide and the preparation of trisulphuryl fluoride) was written under the guidance of Hans-Albert Lehmann.

Kolditz then habilitated in 1957 with a thesis "On compounds of pentavalent phosphorus, arsenic and antimony with fluorine and chlorine".

Kolditz has been married to Ruth, née Schramm, since 1951; the couple has two daughters and lives in Steinförde (a district of Fürstenberg).

The Academy of Sciences of the German Democratic Republic and the ZIAC were dissolved on December 31, 1991, due to the reunification of Germany.

Kolditz's publishing activities include around 350 original publications in academic journals, 37 patents and well over 200 colloquium lectures.

On October 30, 1981, Kolditz was elected President of the National Front of the German Democratic Republic, succeeding Erich Correns.