Cortical neuron differentiation using forced NGN2 expression
Beatrice Weykopf
Abstract
This is a modified protocol based on (Zhang et al.2013 and Meijer et al., 2019) to generate cryopreserved NGN2 neurons, using hPSCs that carry a doxycline-inducible NGN2 cassette.
The voluming are calculated for 10cm TC dishes and should be adapted accordingly
Steps
Overview
D0
Seed 4x106single cells onto 1x10 cm dish (coating MG-GFR or with GF 2mg) in iPSC medium supplemented with 10 µM RI in 7ml medium
D1
Add 8ml KSR with 2µg/ml DOX
D2
9ml 1:1 KSR/N2B w/o B27 2µg/ml DOX and 5µg/ml Puro
Ensure 24h window between this media change and the previous one
D3
10ml N2B containing 2µg/ml DOX) and 5µg/ml Puro
D4
10 ml NBM containing 2µg/ml DOX, 5µg/ml Puro, BDNF 10µg/ml , GDNF 10µg/ml , CNTF 10µg/ml
D5
10 ml NBM containing 2µg/ml DOX, 5µg/ml Puro, BDNF 10µg/ml , GDNF 10µg/ml , CNTF 10µg/ml and 10µM DAPT
D6 AraC treatment
10 ml NBM 2µg/ml DOX, 5µg/ml Puro, BDNF 10µg/ml, GDNF 10µg/ml, CNTF 10µg/ml, 10 µM DAPT
add 3 µM AraC varies between cell lines
! Discard AraC trash according to environmental health guidelines!
D7 AraC treatment
10 ml NBM 2µg/ml DOX, 5µg/ml Puro, BDNF 10µg/ml, GDNF 10µg/ml, CNTF 10µg/ml, 10 µM DAPT
add 3 µM AraC varies between cell lines
! Discard AraC trash and used medium according to environmental health guidelines!
D8
2x wash with 5ml NBM w/o GF to remove AraC completely
add 8-10 ml NBM 2µg/ml DOX, 5µg/ml Puro, BDNF 10µg/ml, GDNF 10µg/ml, CNTF 10µg/ml and
10 µM DAPT
! Discard AraC trash and used medium according to environmental health guidelines!
D9
add 8-10 ml NBM 2µg/ml DOX, 5µg/ml Puro, BDNF 10µg/ml, GDNF 10µg/ml, CNTF 10µg/ml and
10 µM DAP
D10 Cryopreservation
remove medium
1x wash with 4mLl PBS
add 4mL Accutase supplemented with 10µM RI for 90-120min at37°C
After incubation time; If needed add 200µL DNAse I
Add 3mL NBM and dissociate using 10 ml serological pipette
Pool 3x10cm dishes and collect cells in 1x50 ml falcon after pipetting through a 40µm cell strainer on Ice
!collect all cells in a T175 TC falsk on ice!
Rinse dishes with 3 ml NBM
Take a sample from the flask to determine cell number
!Always store cells suspension on ice from now on!
Aliquot pooled cells into 15 ml falcons and centrifuge at 300g for 5min at 4˚C
Freeze cells in 1.5M or 3M aliquots and store at -80˚C overnight and transfer the next day into the liquid nitrogen tank
Freezing medium:
70% KOSRM
20% 1M Trehalose
10% DMSO
