LaCava Research Wiki

Initiated September 2017

October 22, 2020- RNA prep from CRC with and without EDTA

Hua30th October 2020 at 4:24pm

RNA prep from CRC with and without EDTA

Date: 10/22/20

References /Wiki entries

August 5, 2020 - anti-ORF1 IP with EDTA or MgCl2

June 17, 2020- CRC (159_185_174) anti-ORF1 IP

June 10, 2020 - CRC (162_185_197_197_268_284) anti-ORF1 IP

09/09/19 - RNVC Testing – RNA Prep from MT302 and 162T

Everything should be done RNA-grade with nuclease-free reagents, clean bench and pipets with RNase Zap; Use newly prepared buffers and new boxes of tips and tubes etc. whenever reasonably possible. Change gloves often!

RNasin: Recombinant RNasin® Ribonuclease Inhibitor (Promega, Cat # N2515)

RNasin will be used at varying concentrations; Prepare individual tubes of each buffer for each sample

Direct-zol RNA MicroPrep (Zymo Research, Cat # R2060)

Extraction/Wash buffers with Protease and RNase inhibitors:

20mM HEPES, pH7.4, 500mM NaCl, 1% Triton X-100 with or without 25mM EDTA

Extraction/Wash buffers were made with Nuclease-free water (the stock solutions are nuclease free) with Protease inhibitors used at 1x during extraction and washes; RNasin was used @ 1:40 in extraction buffer and 1:250 in wash buffer

Cell Line / CRC:

N2102Ep Endogenous L1

174 Metastatic carcinoma (Breast)

185 MMMT (Ovary)

Scale: 50mg scale with 10ul anti-ORF1 beads per reaction

Weigh out the following powder

50mg of N2102Ep (- EDTA)

2x 50mg of 174T (+/- EDTA)

1x 50mg of 185T (- EDTA); 100mg 185T (2x 50mg reaction +EDTA: 5’ and 15’ IP)

Resuspend the powder by vortexing, no sonication

Spin @ 20k rcf, 4°C for 10’ (Eppendorf Centrifuge 5417R)

Save 35ul of tumor supernatant for RNA prep (“Input”); snap freeze RNA portion in 250ul of Trizol in liquid nitrogen

During spin, wash 60ul anti-ORF1 beads with extraction buffer that does NOT have RNasin added (to conserve RNasin).

Set up IP with 10ul of anti-ORF1 beads per 50mg reaction

1) N2102Ep-EDTA

2) 174T-EDTA

3) 174T+EDTA

4) 185T-EDTA

5) 185T+EDTA

6) 185T+EDTA_5’ IP

IP @ 4°C for15’, except #6 (get tubes and Zymo columns ready while IP is going)

Save 20ul of tumor supernatant for RNA prep (“FT”); snap freeze RNA portion in 250ul Trizol in liquid nitrogen (Skip RNA prep for FT this time)

Wash 2x 250ul with wash buffer

Switch beads to fresh tubes at 2nd wash step Trizol Elution: Elute in 250ul of Trizol

  • all steps from here may be performed at RT if not mentioned otherwise

Vortex for 1min, place the tubes aside (can be on ice or RT, Trizol extract is stable at RT)

Spin the PhsMkr tube at 16k RCF, 30 sec

Add 50ul ChlrFm and 25ul water to the PhsMkr do this immediately before adding TriZol elutions or (perhaps safer still) immediately after transfering elutions to the PhsMkr tube. Adding ChlrFm/water too far in advance may cause a failure. not adding the water will cause the PhsMkrto fail and 'swallow' the aqueous portion of the TriZolreagent mix.

Collect the elution (“E”, pulse spin, place on magnet) and transfer to the PhsMkr tube

Mix by hand, vigorously for 15 sec

Incubate 2 min @ RT with end-over-end mixing this step is almost certainly dispensable for IP - it is supposed to be time for RNPs to dissociate.

Spin 16k RCF, 4C (not important, Trizol extract is stable at RT), 5 min

Transfer the aqueous phase to a new tube by pressing pipette tip against wall of tube; avoid puncturing the Phasemaker gel

Add an equal volume of 100% EtOH (~185uL) to each sample and mix thoroughly, vortex and pulse spin

Transfer the mixture to a Zymo-Spin IC column in a collection tube and centrifuge @ 16,000rcf for 30 seconds (to process samples > 700ul, reload the column and repeat Step 2)

Add 400ul Direct-zol RNA PreWash to the column and centrifuge @ 16,000rcf for 30 sec onds. Discard the FT and repeat this step. Use the vacuum-trap system to clear the liquid from the tubes both times

Add 700ul RNA Wash Buffer to the column and centrifuge for 2 minutes @ 16,000rcf to ensure complete removal of the wash buffer. Transfer the column carefully into an RNase-free tube.

To elute RNA, add 6ul of RNase-Free Water directly to the column matrix and centrifuge @ 16,000rcf for 30 seconds.

Send 1.5ul of 1:10 diluted “Input” and 1.5ul of Elution for pico chip bioanalyzer analysis.

1) Input_N2102Ep-EDTA

2) Input_174T-EDTA

3) Input_174T+EDTA

4) Input_185T-EDTA

5) Input_185T+EDTA

6) E_N2102Ep-EDTA

7) E_174T-EDTA

8) E_174T+EDTA

9) E_185T-EDTA

10) E_185T+EDTA

11) E_185T+EDTA_5’ IP

Bioanalyzer result

https://drive.google.com/file/d/1Pb0hp-WlhWx43lM8LNMQNPbTm31p3CN_/view?usp=sharing