Question

are there any disadvantages of single stranded dna​

Answer 1

ANSWER

• Single stranded DNA can be found in many viruses.

Example - Parvoviridae

                                        - They infect mammalian cells.

• They are unstable.

• They fold up into different shapes

• Studies show that single-stranded DNA is mainly found during the period of DNA synthesis.

NOTE

• DNA usually exists as a pair of strands that are held tightly together.

• These two long strands coil around each other, in the shape of a double helix.

                                                     

Answer 2

Answer:

Single-stranded DNA (ssDNA) is produced from Escherichia coli BIOBlue cells transformed with plasmid pDEA-7Z f(+) using the helper phage VCSM13. The latter stages of this procedure use a revised version of the Qiagen supplementary method: Isolation of ssDNA from M13 phage using Qiagen plasmid kits .

Plasmid pDEA-7Z f(+). This 3.0 kb plasmid contains a unique PstI site and derives from the replacement of the ScaI–BsaI fragment of pGEM-7Z f(+) (Promega) with the ScaI–BsaI fragment of pBR322 (Promega) (Shah, Bennett, & West, 1994a). A stock of form I plasmid DNA is prepared using a Qiagen plasmid maxi kit.

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E. coli BIOBlue chemically competent cells (Bioline; cat BIO-85037).

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Antibiotic stocks: Ampicillin (50 mg/mL), tetracycline (10 mg/mL), kanamycin (70 mg/mL).

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2 × Yeast Tryptone (YT) media.

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20% (w/v) Glucose.

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Helper phage VCSM13 (Agilent; cat 200251).

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PEG 6000 (or PEG 8000), NaCl.

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M2 buffer: 1% (v/v) Triton-X100, 500 mM guanidine-HCL, 10 mM MOPS pH 6.5. Store at room temperature.

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Qiagen-tip 500, buffers QBT, QC, and QF (Qiagen Maxi Kit; cat 12162).

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50 mL Polypropylene Falcon tubes.

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Ethanol.

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Isopropanol.

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TE buffer: 10 mM Tris–HCl pH 8.0, 1 mM EDTA.

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Agarose.

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Horizontal gel electrophoresis equipment (Bio-Rad wide mini-sub cell GT system or equivalent).

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TAE electrophoresis buffer: 40 mM Tris base, 1.1% (v/v) glacial acetic acid, 1 mM EDTA.

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Ethidium bromide stock solution (10 mg/mL).

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10 × Agarose gel loading buffer (50 mM Tris–HCl pH 8.0, 50% (v/v) glycerol, 0.2% (w/v) xylene cyanol, and 0.2% (w/v) bromophenol blue).

MethodsExplanation: