Step 2: Generation of the pTrcHis2A(Kan) vector containing glargine proinsulin.Commercially available pTrcHis2A(Kan) vector was modified to include a Kanamycinresistance gene in the middle of the Ampicillin resistance gene to negate the Ampicillinresistance prior to insertion of the proinsulin sequence into the vector. Ampicillin resistanceheightens the potential for allergic reactions to preparations made using vector constructs thatinclude the Ampicillin resistance gene. Therefore it is preferable to eliminate the Ampicillinresistance in the constructs that are prepared and used.