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Herein we have investigated how efficiently pET plasmids are maintained using these two fragments. The study reveals that pET plasmids are efficiently maintained with both Tn3.1 and Tn903.1 genetic fragments prior to the induction of recombinant protein production, and over short induction times (i.e., 2\u00a0h). However, over longer induction times (i.e., 20\u00a0h), the efficiency of plasmid maintenance depends on the host strain used, and the type of antibiotic selection cassette used. Based on our collective observations, we have 2 general tips for efficiently maintaining pET plasmids during recombinant production experiments.\n                    <jats:list list-type=\"bullet\">\n                      <jats:list-item>\n                        <jats:p>\n                          Tip #1: Use a strain with lowered levels of the T7 RNA polymerase, such as C41(\n                          <jats:italic>DE3<\/jats:italic>\n                          ). pET plasmids will be efficiently maintained over long induction times with both the Tn3.1 and Tn903.1 genetic fragments, regardless of whether antibiotics are present during cultivation.\n                        <\/jats:p>\n                      <\/jats:list-item>\n                      <jats:list-item>\n                        <jats:p>\n                          Tip #2: If a strain with higher levels of T7 RNA polymerase strain is necessary, such as BL21(\n                          <jats:italic>DE3<\/jats:italic>\n                          )), keep induction times short or use a plasmid containing a Tn903.1-type fragment and select with kanamycin.\n                        <\/jats:p>\n                      <\/jats:list-item>\n                    <\/jats:list>\n                  <\/jats:p>","DOI":"10.1007\/s00294-023-01276-0","type":"journal-article","created":{"date-parts":[[2023,11,8]],"date-time":"2023-11-08T06:02:28Z","timestamp":1699423348000},"page":"277-287","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Tips for efficiently maintaining pET expression plasmids"],"prefix":"10.1007","volume":"69","author":[{"given":"Diana","family":"Khananisho","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alister J.","family":"Cumming","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daria","family":"Kulakova","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrick J.","family":"Shilling","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel O.","family":"Daley","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2023,11,8]]},"reference":[{"key":"1276_CR1","doi-asserted-by":"crossref","unstructured":"Aguilar Lucero, D., Cantoia, A., Ceccarelli, E.A., Rosano, G.L., 2021. 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