Description
𧬠Cefotaxime Sodium β a third-generation cephalosporin used to eliminate Agrobacterium after co-cultivation in plant transformation protocols. The antibiotic of choice because it has minimal phytotoxicity compared to carbenicillin.
| π§ͺ CAS | 64485-93-4 | βοΈ MW | 477.44 g/mol |
| π¬ Grade | TC / Microbiological | π‘οΈ Storage | β20 Β°C; use within 2 weeks once dissolved |
𧬠Why cefotaxime after Agrobacterium co-cultivation?
After co-cultivation, living Agrobacterium cells continue to infect plant tissue, causing bacterial overgrowth that kills the culture. Cefotaxime kills Agrobacterium by inhibiting cell wall synthesis (Ξ²-lactam mechanism) β importantly, it does NOT select for transformed plants (kanamycin does that) but eliminates the bacteria. Uniquely, cefotaxime has minimal phytotoxicity even at high concentrations and β unlike carbenicillin β does not promote adventitious shoot growth.
𧫠Working concentrations
| Use | Concentration | Notes |
|---|---|---|
| Standard Agrobacterium elimination | 100β250 mg/L cefotaxime | Add to selection medium for 2β4 weeks |
| Stringent elimination (recalcitrant spp) | 250β500 mg/L | For persistent Agrobacterium |
| Combined with kanamycin (selection) | 200 mg/L cef + 50 mg/L kan | Dual purpose |
| Tobacco transformation (classic) | 100β250 mg/L | Regeneration medium |
π§ͺ Stock prep
Dissolve in sterile distilled water. Prepare 200 mg/mL stock, filter-sterilise, aliquot (1 mL) and store at β20 Β°C. Thawed aliquots are stable at 4 Β°C for 2 weeks. Do not autoclave.
β οΈ Never autoclave cefotaxime β heat degrades the Ξ²-lactam ring. Always add by filter-sterilised stock to cooled medium. Cefotaxime degrades at RT within 24β48 hours in solution β always use fresh stocks.
Reviews
There are no reviews yet.