Bradford assay for insulin: discrepancies between standard curve and sample concentration during crystallisation?

Hi there, I would like to determine the unknown concentration of human insulin in my sample during crystallisation (the concentration range is roughly 0.5 -2 mg/ml, whereas the initial...

06 February 2021 9,370 7 View

Calculate pH after addition of base?

04 February 2021 2,232 4 View

Western blot with very acidic proteins, any suggestions?

I am trying to do a Western Blot to detect acidic proteins (~30kDa) that have a PI of ~3.5, due to the presence of Asp and Glu repeats. The proteins are about 80% pure. After I ran them on...

24 January 2021 7,226 3 View

How does one create IFORM contours?

Hello: Can anyone assist with plotting IFORM contours. I have been trying to plot contours using Hs and Tp as variables. The marginal distribution is a GPD-Kernel density and the conditional...

12 December 2020 4,355 3 View

Hey, how is it possible to detect whether a change in the magnitude of the coeffcient of the independent varibale is significant?

How can I differentiate insignificant from significant changes in Magnitude of the coefficient of the independent variable after a Control variable is included in the Regression. To put it...

09 December 2020 8,317 6 View

How can I transfer heat between groups in Gromacs?

Is it possible to transfer heat from one group to another using simulated aneeling technique in the Gromacs software? I would like to transfer heat from a gold nanoparticle (group 1 from 310 to...

20 November 2020 9,062 3 View

Measuring viscosity and density under high pressure?

I need the density and viscosity of a molecular fluid under relatively high pressures, I expect something around 500 MPa. This kind of measurement is way outside my field, and I can find only very...

19 October 2020 2,812 3 View

Would ER NiCrMo-3 be the best option for weld overlay of carbon and low alloy steels?

Alloy 625 is the most popular alloy for weld overlay. Without considering the price factor, would NiCrMo-3 be the best technical option for weld overlay of API 5L and low alloy steels, in general,...

24 August 2020 2,478 4 View

What formula to get the number of masks needed to wear to prevent 1 infection?

Hi everyone ! I have a challenging time to crack the code in the following analysis...

27 July 2020 3,915 1 View

Dose-response on non-Michaelian response enzymes, how?

Hello For typical dose-response assays, our lab usually uses steady state intervals for defining the difference between control and tested compound. For those assays, we typically use the angular...

23 July 2020 8,662 2 View

Waters 2707 HPLC autosampler problem?

I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...

02 March 2021 1,408 1 View

How optimize the Size Exclusion Chromatography?

Hello! I'll do a size exclusion chromatography, but I only have an open column, and I'll perform the peptide extraction from yeast, using buffer lysis (sodium phosphate 50 mM/NaCl 30 mM/DNAse and...

01 March 2021 2,215 2 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

Any research papers for extraction of nutrient deprivation on macroalgae? Analysed by HPLC-UV and GC/MS. Possibly from macroalgae genus Rhizoclonium?

I am doing my thesis on the nutrient deprivation on the macroalgae Rhizoclonium sp. I will be analysing the levels over a period of roughly 5 days by HPLC-UV and GC/MS. I will be using seawater as...

28 February 2021 6,477 1 View

Do you kow of any database containing data on retention time, log P and polarizability for a large number of molecules?

Hi, I am a chemistry undergraduate doing my dissertation project on HPLC. In my project, I need to predict the HPLC retention time of 20 aromatic molecules, the calibration set. To do this I will...

24 February 2021 2,602 1 View

Any easy method of analyzing vitamin D in foods by HPLC?

Looking for method of extracting and analyzing vitamin D in foods by HPLC

24 February 2021 7,524 7 View

What HPLC Marker(s) should be used to detect anthocyanins in a sample?

What HPLC Marker(s) or standard is used to detect and quantify anthocyanins such as Delphinidin, Cyanidin in a given sample of plant extract?

23 February 2021 1,832 4 View

HPLC baseline failure (ACN/Water)?

My baseline increases without any explanation, it is only fixed by changing the solution B, will it be the column? Reagents? Bomb? Detector? Solution A: H3PO4 0.01% IN WATER Solution B: H3PO4...

21 February 2021 5,656 3 View

Which vial septa the right one to be used for HPLC?

This is the unanswered question stored very long in my mind and till now I could not find a right answer. Google search educated me that the red surface is the PTFE material compatible to wider...

21 February 2021 546 3 View

What is the stability of 2 3-dihydroxyquinoxaline in acidic water?

I'm developing a UHPLC assay, and the fluorescent product is 2,3-dihydroxyquinoxaline. The reaction to produce this requires hydrochloric acid (about 1.2 M). Will storage in this acidic...

20 February 2021 5,820 4 View