Rui:SingelCell

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Revision as of 22:34, 12 January 2011 by >RuiLiu (→‎3. 1st strand cDNA synthesis)
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Background

  • Goal: the smallest functional unit; the exact quantity; full-length RNAs; sense vs anti-sense; all classes; at single-base resolution
  • Step 1: single cell; exact quantity; the 3' end; mRNA; RNAseq

Protocols

1. Single cell capture

1. Single cell capture by mouth pipetting [up to ~0.1 ul]

-Maintain the integrity of living single cells before lysis (dissociation - transfer - wash - transfer)
-PBS alone will cause tight attachment of cells to dish/micropipette, leading to rupture/loss of cells.

2. Cell lysis

1. Cell lysis protocol [up to ~4.55 ul] modified from Tang 2010, NProtocol, 5: 516

-Mild lysis buffer to ensure efficient lysis (thoroughly and completely lysed) w/o severely interfering with RT efficiency
-Positive control to establish the protocol (total RNA, 10pg, 50pg, 100pg, 500pg)
-Negative control to rule out the contamination from the start
UP1 primer
Original (48bp): 5' ATATGGATCCGGCGCGCCGTCGACTTTTTTTTTTTTTTTTTTTTTTTT 3'
Modified (72bp) T7 promoterpoly-banI-(dT): 5' AAACGACGGCCAGTGAATTGTAATACGACTCACTATAGGCGC-GGCACC-(T)24 3'
stock solution: 100 uM
working solution for RT: 0.5 uM (1 ul to 199 ul n-f water)
Cell lysis buffer
--------------------------------------------------------------
Componet	 Original []	Volume (ul)	Final []
-------------------------------------------------------------- 
PCR buffer II	 10*	        0.45	        0.9*
MgCl2	         25 mM	        0.27	        1.35 mM
NP40	         10%	        0.225	        0.45%
DTT	         0.1 M	        0.225	        4.5 mM
SUPERase-In 	 20 U/ul	0.045	        0.18 U/ul
RNase inhibitor  40 U/ul        0.045	        0.36 U/ul
UP1 primer	 0.5 uM	        0.125	        12.5 nM
dNTP mix	 2.5 mM each	0.09	        0.045 mM each
N-F water		        2.975	
Total		                4.45	        in 5ul
--------------------------------------------------------------
use fresh made lysis buffer
2.1 Seed the cell into the 0.5 ml PCR tube with 4.45 ul lysis buffer 
2.2 Centrifuge for 30s at 7,500g at 4C
2.3 Put on ice immediately
2.4 Incubate at 70C for 90s
2.5 Put on ice immediately
2.6 Centrifuge for 30s at 7,500g at 4C
2.7 Put on ice immediately for 1min

3. 1st strand cDNA synthesis

1. 1st strand cDNA synthesis [up to ~5 ul] modified from Tang 2010, NProtocol, 5: 516

RT reaction mix
----------------------------------------------------------------------------------
Componet	                         Original []	Volume (ul)	Final []
---------------------------------------------------------------------------------- 
SuperScript III reverse transcriptase	 200 U/ul	0.33            12.2 U/ul
RNase inhibitor         	         40 U/ul        0.05	        0.4 U/ul	        
T4 gene 32 protein	                 1-10 U/ul      0.07	        0.07 U/ul	        
Total		                         	        0.45 
----------------------------------------------------------------------------------
Prepare and maintain on ice before use
3.1 Prepare RT mix and add 0.45 to each tube
3.2 Incubate at 50C for 30min
3.3 Inactivate the reverse transcriptase at 70C for 15min
3.4 Centrifuge tubes for 30s at 7,500g at 4C
3.5 Put on ice immediately for 1min 

2. 1st strand cDNA synthesis [up to ] using invitrogen kit

4. Free primer removal [up to 6 ul]

Exonulease I mix
----------------------------------------------------------------------------------
Componet	         Original []	Volume (ul)	Final []
---------------------------------------------------------------------------------- 
Exonuclease I buffer 	 10*	        0.1             1*
N-f Water         	                0.8	        	        
Exonuclease	         5 U/ul         0.1	        0.5 U/ul	        
Total		                        1 	         
----------------------------------------------------------------------------------
Prepare and maintain on ice before use
4.1 Prepare Exonulease I mix and add 1 ul to each tube
4.2 Incubate at 37C for 30min
4.3 Inactivate the reaction at 80C for 25min
4.4 Centrifuge the tube for 30sec at 7,500g at 4C 
4.5 Put on ice immediately for 1min

5. 3' poly(A) tailing [up to 12 ul]

TdT reaction mix
--------------------------------------------------------------
Componet	 Original []	Volume (ul)	Final []
-------------------------------------------------------------- 
PCR buffer II	 10*	        0.6	        1*
MgCl2	         25 mM	        0.36	        1.5 mM
dATP	         100 mM	        0.18	        3 mM
RNase H         2 U/ul         0.3	        0.1 U/ul
TdT     	 15 U/ul	0.3	        0.75 U/ul
N-F water		        4.26	
Total		                6	        
--------------------------------------------------------------
5.1 Prepare TdT mix and add 6ul to each tube
5.2 Incubate at 37C for 15min
5.3 Inactivate the TdT at 70C for 10min
5.4 Centrifuge for 30s at 7,500g at 4C
5.5 Put on ice immediately for 1 min

6. 2nd strand cDNA synthesis [up to 22 ul per tube, 4 tubes]

UP2 primer
sequence: ATATCTCGAGGGCGCGCCGGATCCTTTTTTTTTTTTTTTTTTTTTTTT
stock solution: 100 uM

PCR reaction mix with UP2 primer
--------------------------------------------------------------
Componet	 Original []	Volume (ul)	Final []
-------------------------------------------------------------- 
Ex Taq buffer	 10*	        7.6	        1*
dNTP mix	 2.5 mM         7.6	        0.25 mM	        
UP2 primer      100 uM         0.76	        1 uM
Ex Taq HS     	 5 U/ul	        0.76	        0.05 U/ul
N-F water		        59.28	
Total		                76	        
--------------------------------------------------------------
6.1 Divide TdT reaction mix into 4 tubes with 3 ul per tube
6.2 Prepare PCR mix and add 19 ul to each tube 
6.3 PCR cycle: 95C 3min; 50C 2min; 72C 10min; 1 cycle
6.4 Put on ice for 1min
6.5 Centrifuge tube for 30s at 7,500g at 4C
6.6 Put on ice immediately for 1min

7. PCR amplification [up to 41 ul per tube, 4 tubes]

PCR reaction mix with UP1 primer
--------------------------------------------------------------
Componet	 Original []	Volume (ul)	Final []
-------------------------------------------------------------- 
Ex Taq buffer	 10*	        7.6	        1*
dNTP mix	 2.5 mM         7.6	        0.25 mM	        
UP1 primer      100 uM         0.76	        1 uM
Ex Taq HS     	 5 U/ul	        0.76	        0.05 U/ul
N-F water		        59.28	
Total		                76	        
--------------------------------------------------------------
7.1 Prepare PCR mix and add 19 ul to each tube
7.2 PCR cycle: 95C 30s; 67C 1min; 72C 6min (+6s per cycle); 20 cycle; 4C hold
7.3 Centrifuge tube for 30s at 7,500g at 4C
7.4 Store at -80 up to 6 months

8. QC and DNA purification [50 EB buffer]

8.1 Combine the 4 tubes for each sample
8.2 Take 10 ul mix for QC
    1~2ul of 10-fold dilute for a 20ul SYBR Green qPCR (GAPDH, HPRT, ACTB etc.) for RNA quantity and DNA contamination
    Rest: gel check for size and quantity
8.3 Purify the remaining PCR product by EtOH precipitation and suspend w/ 50 ul EB buffer
    Add 1/10 V 3M NaOAc, 0.05-1μg/μl glycogen (?), and 2.5 V EtOH to each tube
    Incubate at -80 for 1hr
    Centrifuge at 10,000g for 30min
    Wash w/ ice-cold 70% EtOH

IVT-based protocol

modified from RiboAmp HS PLUS Amplification Kit, ABi, Cat#

Circulation-based protocol

Nextera library preparation

2011

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