いろんな方法をためした結果以下の方法が、一番再現よく、収量もよくお気に入りです。
dsDNAをPCRをラベルして、いらない方のStrand(末端がリン酸化されたstrand)をNucleaseで特異的に分解する方法です。
Good luck
Preparation of single strand long DNA probe
01. Phosphorylation of oligonucleotide
a. 5' phosphorylation
Mix following mixture
2 ul of 100 uM oligonucleotide
4 ul of 10 x Kinase Buffer A
4 ul of 10 mM ATP
2 ul of 10 U/ul T4 PNK (Nippon Gene)
28 ul of H2O
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total 40 ul
Incubate it at 37C for 60 min.
add 2 ul of 100 mM DTT (final 5 mM)
Incubate it at 37C for 60 min.
b. Purify oligonucleotide with MicroSpin G-25.
c. EtOH precipitation
d. dissolve the precipitant with 20 ul of H2O (final 10 uM).
02. Probe Amplification by PCR
a. direct labeling by PCR
2.5 ul of 10 x ExTaq buffer
1 ul of 2 mM dNTP mixture ** (2 mM dA, dG, dCTP and 1 mM dTTP)
1 ul of 1 mM Biotin-16-dUTP (Roche)
2 ul of 10 uM 5' P-primer
2 ul of 10 uM ICON primer
0.5 ul of ExTaq
1 ul of template DNA
15 ul of H20
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total 25 ul / 40 cycle
yield: ~ 1.5 ug / 25 ul reaction
incorporation efficiency : Biotin-14-dCTP (invitrogen) << Biotin-16-dUTP (roche)
b. Purify with Qiaquick PCR purification kit. Elute with 30 ul of EB
c. Quantify the amount of DNA. |
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