Options for Carboxylic acid and Amine conjugation in presence of Thiols?

More August Hemmerla's questions See All

How to correct info about an article published?

how do you correct information about a publication I added?

30 January 2024 1,476 2 View

What are some statistical tests I can run on time series data?

I am measuring the expression of a fluorescent protein over a period of 4 hours (15 min intervals), testing 4 different conditions with 2 control groups (one positive for expression of the...

23 March 2023 1,996 4 View

Tips for successful PCR of amplicon over 1kb?

I am attempting to amplify out a 1375bp segment of gDNA and I'm wondering what the ideal PCR parameters would be. On my first attempt, I ran a touchdown pcr and subsequently ran the samples on an...

30 April 2021 7,212 4 View

Recommended culture volume/pellet mass for BL21(DE3) genomic DNA extraction?

I am using the NEB Monarch Genomic DNA Purification Kit to extract gDNA from BL21(DE3) cells. The protocol says to use a maximum of 2x10^9 cells but does not mention a recommended culture volume...

25 April 2021 4,181 2 View

Why does different software yield different values for Tajimas D and nucleotide diversity?

Hi! I have a set of CO1 sequences (n=18 and 657 sites) for 5 species from the same genus which I have aligned in MEGA X. I want to find out the nucleotide diversity (pi), number of segregating...

30 March 2021 1,510 5 View

When designing mutagenesis primers, what is the difference between those that anneal back-to-back compared to those that have overlapping 5' ends?

For site directed mutagenesis primer design, specifically those designed to make single-nucleotide substitutions, I have seen methods that utilize back-to-back primer pairs that anneal at the 5'...

11 March 2021 8,246 6 View

Can Streptomycin be Inhibited via camR?

I know that camR inhibits Chloramphenicol via expression of chloramphenicol acetyltransferase, but could that transferase also inhibit Streptomycin, or maybe interact with it in someway that...

05 February 2021 5,761 1 View

What is the danger of adding too much protease inhibitor in your lysate during purification?

During protein purification, a protease inhibitor is added to the lysate (10ul/mL of lysis buffer). Why is this amount of inhibitor desirable? What is the potential danger to the protein if a...

23 November 2020 8,378 7 View

Floating point exception error?

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26 October 2018 7,889 0 View

Mixed Methods

Can we combine two quantitative and qualitative methods in one study? My mind, it should not be merged because the philosophy of both methods is clearly different. Please respond. Thankyou

15 August 2017 7,444 24 View

Separation of organic acids-HPLC?

Hello What should be done to separate and identify organic acids in HPC when their RetTime is the same?Like oxalic acid with Propanoic Acid.or acids that have a very close RetTime.

07 August 2024 8,782 3 View

Determining the worth of a point improvement in Hamilton Depression Scale?

Dear readers, Thanks for your attention. I am wondering about the health economic problem of quantifying the value of interventions which a) prevent, b) improve symptom profile and c) ultimately...

05 August 2024 3,246 1 View

Conjugation of PEG-Amine to an Amino Acid Using EDC?

I am attempting to conjugate PEG to an amino acid at the C-terminus, for the purposes of producing nanoparticles. I have been told that PEG modified with amine groups can be used for this purpose,...

31 July 2024 2,033 1 View

Is it possible to use a safer acid instead of monochloroacetic acid to convert bacterial cellulose to carboxymethyl cellulose?

Hi, researchers, Is it possible to use a safer acid instead of monochloroacetic acid to convert bacterial cellulose to carboxymethyl cellulose?

29 July 2024 4,570 0 View

My cfDNA extraction protocol using silica beads works with plasma collected in COD SAGM bags but not with plasma collected in K2 EDTA tubes. Why so?

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28 July 2024 3,559 0 View

EDC carbodiimide and NHS easter 's half life among different pH?

It has been long known that EDC carbodiimide and NHS easter's half life agains hydrolysis are highly related to pH. However, very surprisingly, not yet found a paper giving a table/chart of their...

25 July 2024 8,738 0 View

What is the Principle of Cysteine-carbazole-sulfuric acid reaction with glucose?

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23 July 2024 3,891 0 View

What does the difference \lambda_j - \lambda_{j+1} represent in relation to the conjugate partition of \lambda?

For a partition of an integer \lambda, what does the difference \lambda_j - \lambda_{j+1} represent in relation to the conjugate partition, , with \lambda_j being the j-th element of \lambda?

23 July 2024 8,008 1 View

When I am trying to distill triethyl amine while drying it over calcium hydride. How do I design the setup to let hydrogen escape without losing NEt3?

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21 July 2024 7,284 4 View

Is it possible to conjugate an NHS ester to the N-terminus of a peptide ON RESIN?

So i have a few peptides (synthesized by SPPS and not cleaved from resin) and I want to add a maleimide label. We have NHS-PEG-Maleimide and from literature it is evident that the free amine group...

18 July 2024 4,075 3 View

Nick Gee

Is it important to preserve the thiols? If not, you could try capping them with N-ethyl maleimide before doing the EDC reaction. This definitely works in aqueous systems at around pH 6.5. Another approach would be to use a maleimide-based scavenging resin and then filter out the beads.

August Hemmerla

Hello Nick Gee. Yes I'm trying to preserve the thiol. Would you know of any effective protecting groups?