Tetanus toxoid (TT) is frequently used as a carrier protein for conjugate vaccines, in addition to being a component of the DPT vaccine. TT contains strong T cell epitopes. However, as a toxoided protein, many of the surface lysines are blocked by the toxoiding process. Furthermore, TT is not a uniform product, since each manufacturer has its own specific toxoiding and purification process. Tetanus toxoid also tends to aggregate with age and is not generally affordable in the quantities needed for research and early clinical work. TT heavy chain fragment C (rTTHc) is the the C terminal fragment of the toxin1. rTTHc is devoid of the toxin's enzymatic activity but contains the binding site necessary for uptake of the toxin by neurons2,3 and is the most immunogenic part of the toxin4. Fragment C contains the powerful T cell epitopes of tetanus toxin without the toxicity. FinaBio offers recombinant TTHc (rTTHc), combining the advantages of the toxoid with the reproducibility of a recombinant protein. Our rTTHc is expressed as a properly-folded, soluble protein in E. coli cytoplasm.