LaCava Research Wiki

Initiated September 2017

June 29, 2020 - anti-ORF1 IP using anti-LaORF1 beads

admin2nd July 2020 at 12:52pm

Anti-ORF1 PO testing anti-LaORF1 beads with XL

Date: 06/29/20

Cell lines: MT302 Light _05/24/14, N2102Ep_12/10/19 and NTERA2_12/06/19

Extraction/wash buffer: 20mM HEPES, pH7.4, 1% Tritonx-100, 500mM NaCl (with protease inhibitors)

Scale: 25 or 50 mg per IP reaction with 10ul of anti-LaORF1 beads per 50mg

Beads:

1) anti-LaORF1-5 (nanobody beads, 08/01/19, XL nanobody to beads)

2) anti-LaORF1-5 (nanobody beads, 10/24/19, XL nanobody to beads)

3) anti-LaG94-10 (nanobody beads, 10/24/19, XL nanobody to beads)

XL nanobody to Epoxy beads after conjugation

Take aliquots of beads: 5ul of anti-LaORF1-5 (08/01/19), 30ul of anti-LaORF1-5 (10/24/19), and 5ul of anti-LaG94-10 (nanobody against GFP, 10/24/19) beads, wash once in 1ml of 1xPBS

Resuspend beads in 20mM DMP in Borate buffer (2ml per reaction with 100ul of beads; make this right before use when beads are washing; I am using more DMP solution than needed to ensure that the beads will be mixing well during the XL step below)

Perform XL reaction @ RT on the wheel for 30’.

After 30’, remove the XL solution

Wash beads with 1ml of PBST

Wash beads again with 1ml of TBST for 5’ @ RT

Wash beads again with 1ml of PBST

Wash beads with 1ml of 1x PBS

Wash all beads in 3x 1ml extraction buffer before IP

Anti-ORF1 IP

Weigh out 50mg MT302, 100mg of N2102Ep and 50mg of NTERA2, add 400ul of extraction buffer with protease inhibitors per 100mg of powder (1:4 w/v), vortex to mix

Sonicate 5 x 2 sec at 2 Amp;

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

Collect the supernatant, split it evenly into 6 aliquots

Set up 25mg or 50mg IP reactions with 10ul of beads per 50mg reaction

1) MT302_25mg_5ul LaORF1_080119

2) MT302_25mg_5ul LaORF1_102419

3) N2102Ep_25mg_5ul LaORF1_102419

4) N2102Ep_25mg_5ul LaG_102419 (negative control)

5) N2102Ep_50mg_10ul LaORF1_102419

6) NTERA2_50mg_10ul LaORF1_102419

IP @ 4°C for 30’

After IP, wash 3x 1ml extraction buffer

Switch beads to fresh tubes at 2nd wash step

Elute the beads with 10ul of LDS, 70 °C for 5’ with mixing

Collect the eluate

Add DTT to 50mM to all samples and heat @70 °C for 10’

Run 4-12% Bis-Tris gel to analyze the elution, Sypro stain

1) Unstained Marker_1ul

2) MT302_25mg_5ul LaORF1_080119

3) MT302_25mg_5ul LaORF1_102419

4) N2102Ep_25mg_5ul LaORF1_102419

5) N2102Ep_25mg_5ul LaG_102419 (negative control)

6) N2102Ep_50mg_10ul LaORF1_102419

7) NTERA2_50mg_10ul LaORF1_102419

8) BSA_25ng

9) BSA_100ng

10) Space

11) Prestained Marker_5ul

2 second exposure

Conclusion: Both batches of LaORF1 worked for anti-ORF1 IP. The 2nd batch (10/24/20) seems to have a bigger problem with nanobody leakage even after DMP XL.