Nanobodies are HCAb derived single-domain antibodies found in Chamelidae serum. Their small size, stability, high antigen affinity and ability of expression in bacterial systems are useful assets in research areas, where affinity is a useful property. We used two M33 nanobody mutants, which have MLKL affinity. Mutant nanobodies 4T5 and 3T1 were designed to form a homodimer in the presence of cobalt ions. Expression by autoinduction was performed in BL21[DE3]. Nanobodies were isolated from inclusion bodies and later refolded by sulfonation and renaturation. Purification was done via His-tag and IMAC on FPLC. We removed His-tag by TEV protease cleavage. Size exclusion liquid chromatography was used to test the dimerization of 4T5 nanobody, which did not occur under the conditions that were used.