Hello, does anyone have any experience with packing columns for nano LC? Any suggestions on the tubings and the method used for column packing?

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 to compare different concentrations of nanoparticles for characterization from ICP-MS?

I took measurements of different concentrations of 15 nm and 5 nm Au nano particle solutions. I'm trying to determine which concentration I measured gives the best reading overall. I also...

02 March 2021 7,626 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

I want to performe MALDI-TOF MS for bacterial identification, I would appreciate it if anyone can tell me the matrix solution preparation protocol ?

based on what I've studied on multiple papers, for peptide and protein identification Alpha-cyano-4-hydroxycinnamic acid (CHCA) is an appropriate matrix to use, I also know that the CHCA powder...

26 February 2021 6,799 3 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

Is it efficient to do liquid biopsy to investigate the gene expressions of the tumor?

To do liquid biopsy and look for specific gene expressions there are so many published papers. Thera are different protocols and procedures used to isolate circulating cell free RNA or mRNA from...

23 February 2021 7,326 5 View

How does the injection volume impact LLOQ and ULOQ in regression analysis (LC-MSMS)?

Hello, I have run into an issue that has sparkled a debate at work: is the LLOQ/ULOQ impacted by injection volume under the following circumstances: 1) Same dilution factor of all samples 2)...

23 February 2021 9,159 3 View

Christof Lenz

The benchfly video is very good to start with! We pack our own columns to 50 and 75 um ID, either into Picofrit PG360-75-15-N or into Picotips 360-75-8-N without frit. We also make KSil Frit columns in case we want to run with a discrete emitter. Material is Dr Maisch C18 aq 3A, we pack from 100% MeOH with helium pressure up to 30 cm lengths.