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 -80oC 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 37oC 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
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为了使供输血用的血液能保存一定时间，加入适当的抗凝剂，并尽量防止在保存期发生变质而用的液体。为了防止因糖的消失引起活力降低，尚加入葡萄糖。ACD液（含柠檬酸三钠、柠檬酸、葡萄糖）一般用于血库。添加ACD的血液放在4—6℃条件下保存，可保存三周。另外为防止柠檬酸盐的过量可用加磷酸钠的CPD液。此外还设计了加乳酸钠的ACDL液。如果加入甘油等防冻剂则可长时间冷冻保存红细胞。
目前选择这个都是北京博凌科为生物科技有限公司的
目前正在从新鲜病人肿瘤组织标本中提取细胞悬液进行阳性细胞的筛选，但由于实验室距离医院有3个小时的车程，请问什么储存方法或者储存液能短期保证肿瘤组织中细胞完整性？谢谢
