Antibodies on substrate surface?

Why might my GFP tag be dissociating from my plasmid after transfection?

I have a set of stably transfected cell lines all transfected with plasmids containing GFP tags on the C terminus. During a western blot using anti-GFP antibody, one of my plasmids has dissociated...

01 March 2021 9,310 4 View

Precipitate after adding laemmli buffer to protein solution containing Potassium Acetate?

Hi, I am running a size exclusion chromatography experiment with a buffer containing Potassium Acetate as a salt. I analyse these fractions through SDS-PAGE. After boiling my SEC fractions in...

01 March 2021 2,622 3 View

What is the most suitable server for predicting protein structures in bacteria?

I have used the i-Tasser several times, however it has been unavailable for several days. I tried the swiss-model, but the output was not very pleasant due to the model used. Is there any other...

28 February 2021 4,521 3 View

Do you need the CMV enhancer before the CMV promotor for a proper function of CMV on the gene that follows?

I'm a student and I have to produce a cell line with a knockin for the NRF2 gene with GFP. I have to put a promotor in front of the GFP because the gene will be too far away from the promotor of...

28 February 2021 7,127 2 View

Are protein samples in SDS compatible with ELISA?

I have used an AllPrep DNA/RNA/Protein Mini Kit QIAGEN kit to extract RNA and protein from my samples. At the end of the protein purification, I resuspend my protein in 5% SDS. Will these samples...

28 February 2021 7,370 3 View

How to replicate the well conditions of a crystal hit with 20%(w/v) isopropanol?

I had a crystal hit in a well with 0.1M HEPEs pH 7.5, 10%(w/v) PEG 4000, and 20%(w/v) isopropanol. Why is isopropanol in w/v here if it's just solvent? How do I recreate this well condition?

25 February 2021 9,761 1 View

Problem with ligating 2.8 kb insert into 8.5 kb plasmid?

I am trying to clone 2 copies of the same mammalian gene into the pSF-CMV-Ub-Puro Ascl (contains HindIII, KpnI and NheI cut sites) plasmid. This is what the final product is supposed to look like...

24 February 2021 6,310 3 View

What urea buffer can i use for biotagged protein extraction from streptavidin beads?

Hi all, I have been doing research on biotagged LDB1 proteins in Mel cells. I purify the proteins using M280 streptavidin beads. The yield is very low so I've been trying to optimize it by...

24 February 2021 5,749 3 View

Can I use a protein-devoid condition as my negative control in ELISA?

Hello, I am running a sandwich-type ELISA where I am trying to inhibit a protein-protein interaction using small molecules. For each experiment, I determine my Z' (Z-prime) to determine the...

23 February 2021 7,429 1 View

Is there a way to extract total RNA and protein from cell culture at the same time, without denaturing protein?

Hi all, Is there a way to extract RNA and protein from the same cell culture sample? Because we need to use the protein for gelatin zymography at later time, we are looking for a method that can...

22 February 2021 5,341 5 View

Petr Lepcio

A "competing adsorption" principle is known in polymer composites and nanocomposites. Your experimental system is way more complex, but in theory, I assume that BSA can still act as a displacer to your antibodies. I didn't do the required calculations to verify this hypothesis, though.

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Kanstantsin Syargeevich Livanovich

I doubt BSA can replace chemisorbed molecules from the surface. More possible explanation is following: BSA electrostatically adsorbed on the surface of APTMS and formed thick (up to few um) layer and therefore hide the antibodies. At conditions described (pH 7.4) BSA has negative charge whereas APTMS is highly protonated (pKa is about 10). I am not sure, is it possible to distinguish an APTMS surface and any homogeneous polymeric surface from the AFM and FESEM data?