Competent cells are one of the most basic tools in molecular biology research. Making home-made competent cells are time consuming and has contamination potentials, thus buying commercial competent cells are preferred by most investigators for convenience and efficiency. Different competent cells have different applications. Beyotime provides more than 30 types of competent cells of different bacterial strains such as BL21, ER2566, TOP10, TOP10F’, Tuner (DE3), Turbo, BJ5183, DB3.1, DH10B, DH10Bac, EPI300, EPI400, GT115, C43(DE3) PLysS, ArcticExpress (DE3) pRARE2, ER2566, HB101, JM109, JM109(DE3), MG1655, Stable, and Stbl3, etc.
BL21 Series
BL21 is a prokaryotic expression strain developed at the earliest, based on which series of prokaryotic expression strains such as BL21(DE3), Rosetta, OrigamiB(DE3) are derived.
Beyotime is now launching supercompetent cells for 10 types BL21-detrived strains and their applications are listed in the following table.
| Cat. No. | Product Name | Pack Size | Applications |
| D1009S/M | BL21 Supercompetent cells | 10×100μl/50×100μl | E. coli BL21 ready-to-use chemically competent cells that can be used to express non-toxic proteins. |
| D1011S/M | BL21(AI) Supercompetent cells | 10×100μl/50×100μl | E. coli BL21(AI) ready-to-use chemically competent cells that can be used to express recombinant proteins that are toxic to bacteria or inhibit growth. |
| D1013S/M | BL21(DE3) Supercompetent cells | 10×100μl/50×100μl | E. coli BL21 Star (DE3) ready-to-use chemically competent cells that can be used to express heterologous proteins at ultra-high levels. |
| D1015S/M | BL21(DE3) PLysS Supercompetent cells | 10×100μl/50×100μl | E. coli BL21(DE3) PLysS ready-to-use chemically competent cells that can be used for IPTG-induced recombinant protein expression. |
| D1019S/M | BL21 Star(DE3) Supercompetent cells | 10×100μl/50×100μl | E. coli BL21 Star(DE3) ready-to-use chemically competent cells that can be used to express heterologous proteins at ultra-high levels. |
| D1021S/M | BL21 Star (DE3)pLysS Supercompetent cells | 10×100μl/50×100μl | E. coli BL21 Star (DE3) pLysS ready-to-use chemically competent cells that can be used for heterologous protein expression. |
| D1065S/M | Rosetta(DE3) Supercompetent cells | 10×100μl/50×100μl | E. coli. Rosetta (DE3) ready-to-use chemically competent cells that can be used to express eukaryotic proteins with 6 rare codons. |
| D1067S/M | Rosetta2(DE3) Supercompetent cells | 10×100μl/50×100μl | E. coli. rosetta2(DE3) ready-to-use chemically competent cells that can be used to express eukaryotic proteins with 7 rare codons. |
| D1071S/M | Rosetta-gami B(DE3) Supercompetent cells | 10×100μl/50×100μl | E. coli. Rosetta-gami B (DE3) ready-to-use chemically competent cells that can be used to express eukaryotic proteins with 6 rare codons and disulfide bonds. |
| D1057S/M | Origami2(DE3) Supercompetent cells | 10×100μl/50×100μl | E. coli Origami2 (DE3) ready-to-use chemically competent cells that can be used to express proteins with disulfide bonds. |
ER2566 Supercompetent Cells
ER2566 is a strain obtained by replacing part of the genomic sequence of BL21 with the homologous sequence in K-12. With the 6% genomic sequence of K-12, ER2566 is resistant to DNA damages caused by non-specific nucleases, while not BL21. Therefore, ER2566 is commonly used to express recombinant proteins such as restriction endonucleases, nucleases, and DNA polymerases.
| Cat. No. | Product Name | Pack Size | Applications |
| D1039S/M | ER2566 Supercompetent cells | 10×100μl/50×100μl | E. coli ER2566 ready-to-use chemically competent cells that can be used for recombinant protein expression. |
TPO10 and TOP10F` Supercompetent Cells
TOP10 derived from MC1061 is one of the most commonly used strains in laboratories for gene cloning, blue and white screening, plasmid stable amplification and other molecular biology experiments. Is growth rate is fast (faster than DH5α and slower than Mach1-T1), and clones are visible in 10 hours.
TOP10F` is obtained by transfecting TOP10 strain with the F` factor {lacIq Tn10 (TetR)}, a bacterial intracellular circular DNA appendage (Episome) that cannot be degraded and is independent of genome replication. This factor carrying the lacIq repressor can inhibit the expression of genes downstream of promoters such as trc, tac, and lac. Therefore TOP10F` Supercompetent cells can be used for the amplification of plasmids for toxic protein expression.
| Cat. No. | Product Name | Pack Size | Applications |
| D1087S/M | TOP10 Supercompetent Cells | 20×100μl/100×100μl | E. coli TOP10 ready-to-use chemically competent cells that can be used for efficient DNA cloning and stable replication of high-copy plasmids. |
| D1089S/M | TOP10F` Supercompetent Cells | 10×100μl/50×100μl | E. coli TOP10F` ready-to-use chemically competent cells that can be used for efficient amplification of ssDNA and plasmid DNA. |
Tuner(DE3) Supercompetent Cells
Tuner(DE3) is a B strain deficient in lon and ompT proteases, and also a BL21 strain with mutations in lacZY gene encoding galactoside permease to enable IPTG to enter each E. coli cell at a homogeneous rate, producing a more stringent and homogeneous concentration dependence. The λ phage DE3 region containing the T7 RNA polymerase encoding region is integrated on the chromosome of Tuner, so called Tuner(DE3), by which both T7 RNA polymerase and E. coli RNA polymerasecan can be expressed in Tuner (DE3) strain. Therefore the Tuner(DE3) Supercompetent Cells can be used for protein expression with plasmids such as pET series, pGEX, and pMAL.
| Cat. No. | Product Name | Pack Size | Applications |
| D1091S/M | Tuner(DE3) Supercompetent Cells | 10×100μl/50×100μl | E. coli tuner (DE3) ready-to-use chemically competent cells that can precisely control the homogenization expression of recombinant proteins in all bacterial cells. |
Turbo Supercompetent Cells
Turbo strain derived from Escherichia coli K-12 is one of the most commonly used E. coli, with rapid growth rate. Clones are visible on plates in 6.5 hours and plasmids can be extracted after 4-6 hours growth in nutrient solutions. In addition, it is capable of rapid transformation, and transformation of AmpR vector into Turbo Supercompetent Cells can be completed in 5 minutes.
| Cat. No. | Product Name | Pack Size | Applications |
| D1093S/M | Turbo Supercompetent Cells | 10×100μl/50×100μl | E. coli Turbo ready-to-use chemically competent cells that can be used for rapid amplifications of plasmids in an average of 6 hours. |
BJ5183 Series
BJ5183 series supercompetent cells are mainly used for adenovirus related experiments. Beyotime launches BJ5183 and BJ5183-AD-1 supercompetent cells this time.
The genotype of BJ5183 is endA1 sbcBC recBC galK met thi-1 bioT hsdR (StrR). The double mutations of sbcBC and recBC confer strong recombination ability and facilitate recombination of the transferred target gene with the adenovirus plasmid. Mutation of EndA1 facilitates the stability of the plasmid DNA. StrR makes the cell resistant to streptomycin sulfate.
The genotype of BJ5183-AD-1 is endA1 sbcBC recBC galK met thi-1 bioT hsdR (StrR) [pAdEasy-1 (AmpR)]. Tthe double mutations of sbcBC and recBC confer strong recombination ability and facilitate the recombination of the transferred target gene with the adenoviral backbone plasmid. RecA1 reduces the probability of homologous recombination of the inserted fragment and ensures the stability of the inserted DNA.StrR makes the cell resistant to streptomycin sulfate. pAdeasy-1 makes the cell resistant to ampicillin, but once it is recombined with the shuttle vector, the resistance disappears.
| Cat. No. | Product Name | Pack Size | Applications |
| D1005S/M | BJ5183 Supercompetent Cells | 10×100μl/50×100μl | E. coli BJ5183 ready-to-use chemically competent cells specifically designed for the preparation of recombinant adenovirus plasmids. |
| D1007S/M | BJ5183-AD-1 Supercompetent Cells | 10×100μl/50×100μl | E. coli BJ5183-AD-1 ready-to-use chemically competent cells that can be used for plasmid cloning of adenovirus systems with high recombination capability. |
DB3.1 Supercompetent Cells
The DB3.1 E. coli strain is suitable for the CcdB-mediated forward positive selection and is compatible with the Gateway high-throughput cloning technology. The gyrA462 gene is integrated in the genome, conferring resistance to ccdB gene virulent to bacteria specificly. In addition, the strain is resistant to streptomycin.
| Cat. No. | Product Name | Pack Size | Applications |
| D1025S/M | DB3.1 Supercompetent Cells | 10×100μl/50×100μl | E. coli DB3.1 ready-to-use chemically competent cells that can be used to efficiently amplify plasmids carrying the ccdB virulence gene and to construct clones with the ccdB screening marker. |
DH10B and DH10Bac Supercompetent Cells
DH10B is one of the most commonly used E. coli strains in the laboratory for routine gene cloning and more widely used for genomic library, cDNA library construction and site-specific mutagenesis in eukaryotes.
DH10Bac strain bMON14272 contains mini-F replicon, kanamycin resistance gene, attTn7 locus and lacZα complementation factor. The helper plasmid pMON7124 contains tetracycline resistance and tnsABCD region which expresses transposable protein required for transposition reaction. The exogenously transferred expression vector (usually pFastBac) carrying the T7 transposable element (Tn7 element) carries the gentamicin resistance gene. Thus, positive clones can be screened with plates containing kanamycin, tetracycline and gentamicin.
| Cat. No. | Product Name | Pack Size | Applications |
| D1027S/M | DH10B Supercompetent Cells | 10×100μl/50×100μl | E. coli DH10B ready-to-use chemically competent cells that can be used for efficient cloning. |
| D1029S/M | DH10Bac Supercompetent Cells | 10×100μl/50×100μl | E. coli DH10Bac ready-to-use chemically competent cells that can be used to produce large plasmids required for the baculovirus protein expression system. |
EPI300 and EPI400 Supercompetent Cells
The EPI300 strain contains a mutated trfA gene encoding a protein that promotes high copy replication of plasmid with the oriV replicon. Under non-inductive conditions, when the EPI300 strain containing the oriV ,replicon plasmid is grown in LB/2YT or SOB medium, the expression of trfA gene is suppressed and the copy number of the oriV replicon plasmid is maintained at a very low level. However when an inducer is added to the medium, the copy number of the oriV replicon plasmid is highly increased.
The EPI400 strain is obtained from EC100 by inserting the pcnB gene driven by an inducible promoter after deleting the pcnB gene that increases the plasmid copy number in EC100. Thus, the copy number of plasmids in EPI400 is low under non-inducible conditions and can be increased to normal with the addition of WDEPI-inducible agent I.
| Cat. No. | Product Name | Pack Size | Applications |
| D1035S/M | EPI300 supercompetent Cells | 10×100μl/50×100μl | E. coli EPI300 ready-to-use chemically competent cells that can be used for efficient amplification of plasmid DNA up to 145 kb in length and for cloning of plasmids that have low yields in conventional strains. |
| D1037S/M | EPI400 supercompetent Cells | 10×100μl/50×100μl | E. coli EPI400 ready-to-use chemically competent cells that can be used for cloning a variety of unstable DNA or virulence genes. |
GT115 Supercompetent Cells
GT115 Supercompetent cells contain the SbcCD protein complex that recognizes and excises DNA hairpin structures. Mutations in sbcC and sbcD enhance the stability of hairpin-structured DNA. Meanwhile, the introduction of uidA(DMluI)::pir-116 in GT115 genome allows for π protein expression and enables plasmids containing the R6Kg ori replicon (pCpG-mcs, pCpG-LacZ, pCpG-siRNA...) to replicate normally.
| Cat. No. | Product Name | Pack Size | Applications |
| D1041S/M | GT115 Supercompetent Cells | 10×100μl/50×100μl | E. coli GT115 ready-to-use chemically competent cells can be used to clone DNA sequences containing hairpin structures or repetitive sequences. |
C43(DE3)PLysS Supercompetent Cells
C43(DE3)PlysS can express both T7 RNA polymerase and E. coli RNA polymerase, and thus can be used for protein expression with plasmids such as pET series, pGEX, and pMAL. This strain originates from BL21(DE3), and the introduction of the pLysS plasmid not only confers chloramphenicol resistance but also allows for the simultaneous expression of T7 lysozyme which can bind T7 RNA polymerase to inhibit its transcriptional activity without interfering with IPTG induced expression while reducing the basal expression level of the recombinant protein. Thus, the C43(DE3) PLysS strain has a greater ability to express virulent and hydrophobic proteins.
| Cat. No. | Product Name | Pack Size | Applications |
| D1023S/M | C43(DE3)PLysS Supercompetent Cells | 10×100μl/50×100μl | E. coli C43(DE3) PLysS ready-to-use chemically competent cells can be used for efficient expression of toxic or hydrophobic proteins. |
ArcticExpress (DE3) pRARE2 Supercompetent Cells
ArcticExpress (DE3) carrying the pRARE2 plasmid can expresse the low-temperature adapted cpn10 and cpn60 chaperone proteins which have stronger pro-protein folding functions than the conventional chaperone, GroEL and GroES, at low temperatures. In addition, the pRARE2 plasmid with the chloramphenicol resistance gene can complement the tRNA corresponding to seven rare codons (AUA, AGG, AGA, CUA, CCC, GGA and CGG) which are lacking in E. coli for efficient expression.
| Cat. No. | Product Name | Pack Size | Applications |
| D1003S/M | ArcticExpress (DE3) pRARE2 Supercompetent Cells | 10×100μl/50×100μl | E. coli ArcticExpress (DE3) pRARE2 ready-to-use chemically competent cells can be used for soluble recombinant protein expression. |
HB101 Supercompetent Cells
HB101 belongs to E. coli K12 strain, but carries partial genome sequence of E. coli B strain. This strain does not contain the endA1 mutation and has a high nuclease content in vivo, thus it is important to use the deproteinization solution in plasmid extraction. In addition, HB101 is resistant to streptomycin and does not have lacZΔM15, thus it cannot be used for blue and white screening.
| Cat. No. | Product Name | Pack Size | Applications |
| D1043S/M | HB101 Supercompetent Cells | 10×100μl/50×100μl | E. coli HB101 ready-to-use chemically competent cells can be used for cDNA library construction or cloning and plasmid construction of long DNA fragment with terminal repeats. |
JM109 and JM109(DE3) Supercompetent Cells
The JM109 strain is derived from the E. coli K strain, in which mutation of the hsdR17 gene eliminates restriction endonuclease activity, making the heterologous plasmid DNA not degraded by the endogenous nuclease. Thus it is an ideal strain for extracting high-quality DNA.
JM109(DE3) strain is a strain obtained from JM109 after λDE3 lysogenization. λDE3 contains the T7 RNA polymeras encoding region which is integrated on the chromosome of JM109. This strain can express both T7 RNA polymerase and E. coli RNA polymerase, and thus be used for protein expression of plasmids such as pET series, pGEX, and pMAL.
| Cat. No. | Product Name | Pack Size | Applications |
| D1047S/M | JM109 Supercompetent Cells | 20×100μl/100×100μl | E. coli JM109 ready-to-use chemically competent cells can be used for efficient transformation of conventional plasmids and for plasmid preservation. |
| D1049S/M | JM109(DE3) Supercompetent Cells | 10×100μl/50×100μl | E. coli JM109(DE3) ready-to-use chemically competent cells can be used for both gene cloning and recombinant protein expression. |
MG1655 Supercompetent Cells
MG1655 is a wild-type model strain derived from the E. coli K-12 strain and is suitable for basic microbial research, E. coli gene editing, and industrial fermentation engineering. The strain carries few genetic modifications and the whole genome sequence is publicly available with detailed annotation.
| Cat. No. | Product Name | Pack Size | Applications |
| D1055S/M | MG1655 Supercompetent Cells | 10×100μl/50×100μl | E. coli MG1655 ready-to-use chemically competent cells that can be routinely used for efficient transformation of plasmids. |
Stable Supercompetent Cells
The Stable strain is recommended for retroviral/lentiviral vector systems. Compared to Stbl2 and Stbl3, the endA1 mutation in the Stable strain facilitates plasmid DNA stability, resulting in better plasmid purity and integrity, and thus this strain is suitable for blue-white screening. However, the Stable strain does not have the rapid plasmid amplification properties exhibited by Stbl2.
| Cat. No. | Product Name | Pack Size | Applications |
| D1077S/M | Stable Supercompetent Cells | 10×100μl/50×100μl | E. coli Stable ready-to-use chemically competent cells can be used for cloning of lentiviral or DNA fragments with terminal repeats. |
Stbl3 Supercompetent Cells
Stbl3 is derived from HB101 strain, with the genome sequence containing mutated recombinase to effectively inhibit recombination of terminal repeats of long fragments. Therefore, this stain can be used for efficient transformation, cloning, and amplification of lentiviral vectors and other retroviral vectors containing repetitive sequences.
| Cat. No. | Product Name | Pack Size | Applications |
| D1081S/M | Stbl3 Supercompetent Cells | 10×100μl/50×100μl | E. coli Stbl3 ready-to-use chemically competent cells can be used to clone and amplify vectors containing repetitive sequences, such as lentivirus vectors, or larger and less stable vectors. |