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Description: 

In this experiment, we want to want to compare the levels of endogenous cofilin and TEVp-Cofilin expressed under an inducible promoter with different levels of dox induction. This will allow us to determine what level of expression of cofilin would lead to the

best signal

best signal:

noise ratio

noise ratio of exogenous cofilin to endogenous cofilin. We are planning to transfect HEK293 with TEVp-Cofilin  under a TRE promoter and induce with varying levels of dox. We will then preform a Western blot with an anti-cofilin primary antibody and compare band sizes to test for the relative amounts of endogenous cofilin and exogenous TEVp-Cofilin  in the cells.

 

Cloning

COMPLETE

Description

Making pEXPR TRE:TEVp-cofilin.

Plan
  •  Order TEVp-cofilin 
  •  Golden Gate gBlocks into ggDONR
  •  Transform bacteria with Golden Gate product and plate 
  •  Pick colonies and grow in liquid culture
  •  Miniprep cells and verify product 
  •  Make glycerol stocks
  •  LR into pDEST
  •  Transform, pick colonies and grow in liquid culture
  •  Miniprep cells and verify product
  •  Make glycerol stocks 
  •  Midiprep product

Experiment

Transfection Plan:

Plate 1

Well 1

HEK293

Well 2

HEK293

+ Dummy (

1,000ng

2500ng)

Well 3

 

HEK293

+ Dummy (

500ng

1500ng)

+hEF1a:

GFP

YFP (

500ng

1000ng)

Well 4

 

Well 5
Well 6

 

 

  Image Added

 

 

  

 

Plate 2
Well 7

 

HEK293

+hEF1a:

GFP

YFP (

400ng

1000ng)

+hEF1a:rtTA (

200ng

500ng)

+TRE:TEVp-Cofilin (

400ng

1000ng)

0x
0nM Dox
Well 8

 

HEK293

+hEF1a:

GFP

YFP (

400ng

1000ng)

+hEF1a:rtTA (

200ng

500ng)

+TRE:TEVp-Cofilin (

400ng

1000ng)

1x
1nM Dox
Well 9

 

HEK293

+hEF1a:

GFP

YFP (

400ng

1000ng)

+hEF1a:rtTA (

200ng

500ng)

+TRE:TEVp-Cofilin (

400ng

1000ng)

10x
10nM Dox
Well 10

 

HEK293

+hEF1a:

GFP

YFP (

400ng

1000ng)

+hEF1a:rtTA (

200ng

500ng)

+TRE:TEVp-Cofilin (

400ng

1000ng)

100x
100nM Dox
Well 11

 

HEK293

+hEF1a:

GFP

YFP (

400ng

1000ng)

+hEF1a:rtTA (

200ng

500ng)

+TRE:TEVp-Cofilin (

400ng

1000ng)

1,000x
1000nM Dox
Well 12

 

HEK293

+hEF1a:

GFP

YFP (

400ng

1000ng)

+hEF1a:rtTA (

200ng

500ng)

+TRE:TEVp-Cofilin (

400ng

1000ng)

2,000x
2000nM Dox
Well 13
Image Added
Well 14
Image Added
Well 15
Image Added
Well 16
Image Added
Well 17
Image Added
Well 18
Image Added
Well 19
Well 20
Well 21
Well 22
Well 23
Well 24

 

Controls

Stuff

:

GAPDH: Loading control (how many cells we've loaded onto the gel)

GFP

YFP: Transfection marker (how many transfected cells we've loaded onto the gel)

Protein Sizes:
Protein
Size (kDa)
Cofilin18.5
TEVp-Cofilin 48.6
GAPDH37
GFP
YFP27

Image Removed

We are planning to get
Gels:

Image Added

We have the any kD gels in the lab (expires 2015) and this will work for both our western blot and antibody group's western blot.

Image Added

If we run out of the above gel we are considering getting the 4-25% gel in order to optimize our resolution. This will also work for both our western blot and antibody group's western blot.

Antibodies:


Expected Results:

 Ladder
 LadderHEK293

HEK293

+ Dummy

HEK293

+

GFP

YFP

+ Dummy

HEK293

+

GFP

YFP

+ TEVp-Cofilin 

50    TEVp-Cofilin 
40 GAPDH GAPDH GAPDHGAPDH 
30  
 
YFP
GFP 
YFP 
     
20 Cofilin Cofilin
 
Cofilin Cofilin

 

http://www.thermoscientificbio.com/uploadedFiles/Resources/general-recommendations-for-sds-page.pdf

Results: 

Expand
titleTrial 1
Lane1234567891011
ContentsLadderUntransfectedDummyeYFP

eYFP

rtTa

TEVp-Cofilin

0nM Dox

eYFP

rtTa

TEVp-Cofilin

1nM Dox

eYFP

rtTa

TEVp-Cofilin

10nM Dox

eYFP

rtTa

TEVp-Cofilin

100nM Dox

eYFP

rtTa

TEVp-Cofilin

1000nM Dox

eYFP

rtTa

TEVp-Cofilin

2000nM Dox

Ladder
Protein
Size (kDa)
Cofilin18.5
TEVp-Cofilin 48.6
GAPDH37
YFP27
                            
Image AddedImage AddedImage Added

Odyssey blocked blot.

Cofilin and TEVp-Cofilin bands are not there...

We know that cofilin is present in relatively large amounts and the fact that neither native cofilin nor TEVp-cofilin bands appear might indicate that there is a problem with the anitbody or the antibody treatment of the blot. Both anti-cofilin and anti-eYFP are rabbit antibodies and since eYFP bands show, we can assume that the goat anti-rabbit secondary works.

YFP and GAPDH bands are higher than they should be.

Low signal from GAPDH (relative to YFP)

BSA blocked blot.

Cofilin and TEVp-Cofilin are not here either

There's a lot of background

 
Expand
titleTrial 2

Modifications to Trial 1:

Increased cofilin primary antibody concentration from 1/10,000 to 1/2500 because both cofilin and TEVp-cofilin bands didn't show up in Trial 1

--- Didn't help that much considering the cofilin bands are still not there

Didn't probe for GAPDH because the amount of background that the 800 secondary antibody was producing

--- No background (smile) (although, there wasn't that much background with the odyssey blocked blot in Trial 1)

Also the YFP band (the only one there) is again slightly higher than it should be

Lane1234567891011
ContentsLadderUntransfectedDummyeYFP

eYFP

rtTa

TEVp-Cofilin

0nM Dox

eYFP

rtTa

TEVp-Cofilin

1nM Dox

eYFP

rtTa

TEVp-Cofilin

10nM Dox

eYFP

rtTa

TEVp-Cofilin

100nM Dox

eYFP

rtTa

TEVp-Cofilin

1000nM Dox

eYFP

rtTa

TEVp-Cofilin

2000nM Dox

Ladder
Protein
Size (kDa)
Cofilin18.5
TEVp-Cofilin 48.6
GAPDH37
YFP27

Image Added
Image Added

Next step: I would like to have a positive control. Abcam suggests HeLa lysates (if we have those around in the lab)