BioPioneer’s unique high-throughput format competent cells are arrayed in breakable 24-well, 48-well and 96-well PCR plate.The plates can be separated without scissors into any combination of 8 well strips. DH5alpha is one of the most commonly used E. coli strain for plasmid transformation. Ultra-high efficiency DH5alpha Competent Cells are prepared with unique salt compositions and procedures that result in significantly higher transformation efficiency than those by traditional lab protocols using CaCl2 buffers. Biopioneer’s competent cells are quality controlled by direct comparison to other leading brands of similar products in transformation of ligated plasmids.

Ultra-high efficiency DH5α Competent Cells are suitable for propagation of plasmids of all sizes and preparations.They are recommended for difficult constructs that often yield low colony counts.

Features:

- Widely used strain

- Suitable for 3 min quick protocol

- Efficiency: Constantly above 1 x 10⁹ cfu/µg of supercoiled pUC19 plasmid DNA; higher colony counts than DH5a Competent Cells from other leading suppliers, especially when transforming ligation reactions.

- Conveniently packaged in 60ul aliquot, no repeated freezing in dry ice and alcohol bath.

- Blue/white color screening of recombinants

Genotype:

F’/endA1 hsdR17(rK-mK+) supE44 thi-1 recA1 gyrA (Nalr) relA1 D(laclZYA-argF)U169 deoR

(F80dlacD(lacZ)M15)

Storage:

It has been observed that long term storage of competent cells at -80^oC can actually cause the cells to adapt by increasing the recombination rate. Therefore, BioPioneer Inc. prepares its competent cells frequently at small scales. It is recommended that competent cells be used within 3 months after arrival.

Transformation Protocol

1. Thaw competent cells on ice. It is essential that cells be completely thawed before pipetting. Pipet slowly.

2. Add DNA of your choice (pure DNA or ligation mix) to the cells and incubate on ice for 30 minutes (may use 5 min for subcloning). Heat-shock at 42°C for 30 seconds and put the tube on ice for 1.5-2 minutes.

3. Add 200ul SOC or LB broth and shake the cells at 37°C at 225 rpm for 30-60 minutes.

4. Plate out desired amount on a prewarmed (37°C) plate with the appropriate antibiotic and incubate in a 37^oC incubator.

Quick Protocol:

1. For each transformation, thaw one tube of cells on ice.

2. Mix DNA and cells, incubate on ice for 1-2 min

3. Heat shock in 42°C water bath for 45 sec, or in 37°C water bath for 1.5 min

4. After heat-shock, incubate the reaction on ice for 1 min and spread on plate directly.

The typical 1 hour growing in plain LB may generate 2-3 fold more colonies but is not necessary in most cases.