Vitamin B12 detection & determination?

More Esraa Radhwan's questions See All

Why daily dexamethasone given to rats fed high fat/fructose/salt cause very high mortality rate?

rats were given daily dexamethasone in drinking water corresponding to 0.5 mg/kg or 2 mg/kg. These rats are simultaneously fed 25% fat, 3% salt in diet and 10% fructose in drinking water but...

15 February 2021 7,634 2 View

Do you think that genetic inheritance or the environment is more influential in the development of substance abuse?

Do you think that genetic inheritance or the environment is more influential in the development of substance abuse ?

04 January 2021 1,587 3 View

What factors are contributing to the reemergence of communicable diseases previously thought to be under control?

02 January 2021 5,255 7 View

What are the implications of the behavioral, cognitive, and humanistic learning theories?

What are the implications of the behavioral, cognitive, and humanistic learning theories with respect to content, presentation, learner role, teacher role, and evaluation of learning?

28 December 2020 5,073 3 View

How can i send the Mandelys reference Library file ???

hi to all my dear colleagues, i need your help concerning finding the proper way to send and prepare the library file of references by Mandely??

06 July 2020 383 5 View

I would like to quantify cytokines from mice brain using ELISA, What is the total protein concentration i suppose to add in each well?

Hi everyone I want ant to use ELISA to quantify tnf a ,il-1b and inf g in Half brain of mice. I was wondering if any one has done this exactly before and can tell me which concentration of...

07 May 2019 7,701 3 View

Does BHK (Baby Hamster kidney) cell line have specific regulations to Enter Egypt?

I need to import BHK cells to Egypt, but I'm not sure if there are any regulations for it to Enter!

26 February 2019 4,814 1 View

What does it mean by negative values for number of genotypes identified by a primer in detecting the polymorphism ?

So i am recording the polymorphic statistics of iPBS primers and one of the parameters estimated is R (resolving power). From an equation (0,15x + 1,78 = R) i can detect the number of genotypes...

14 February 2019 9,111 1 View

What is the simplest method to determine the serum concentration of Lead?

Is there a simple, inexpensive method that can be used to accurately measure the serum concentration of Lead--other than the atomic absorption spectrophotometry (AA: graphite furnace and flame)...

12 January 2019 3,187 9 View

How do I know if my data obey Beer's law or not?

Hi all, I would like to know if the data, for a given drug, obtained from the UV/VIS Spectrometer obey Beer's law or not. Is there a general rule? Also, why an Absorbance Reading above one is...

29 December 2018 4,391 6 View

What is the exact mechanism of the antimicrobial effect of local anesthetics?

The antimicrobial effect of local anesthetics has been known for more than 50 years, but it still seems to have an unclear mechanism of action. which bacteria? which concentration? etc etc. ....

27 February 2021 4,450 2 View

Uncertianiny in using dry or wet basis in mixing a sediment with fuel oil?

Hello I'm currently working on a topic related to studying the anaerobic biodegradation of TPH in marine sediments. In this work, sediment should be mixed with fuel oil to a concentration of 20 g...

24 February 2021 9,839 3 View

Advice on growing lactobacillus species in the lab?

Hello everyone, For part of my PhD project, I'm hoping to grow some lactobacillus species in the lab so that I can create standard curves for a qPCR quantification of a faecal sample. However, I...

24 February 2021 3,157 6 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 are the best cations for preparing competent cells, Ca2+ or Mg2+?

I have been reading various articles and most state that treatment with CaCl2 produces higher efficiency of transformation than MgCl2. Can anyone explain why Ca2+ is better than Mg2+ at...

16 February 2021 8,519 5 View

Would using an asRNA for repressing transcription of a high expression Listeria monocytogenes non-coding RNA harbored in a plasmid be a viable option?

Hello all, I am interested in deleting a highly expressed non-coding RNA located on a Listeria monocytogenes plasmid. Currently, there are not any optimized gene deletion methods for Listeria...

09 February 2021 4,994 1 View

Review Papers regarding transcriptional regulations & promoter types/classes in Gram positive bacteria?

Dear fellow researchers, Could you please suggest me excellent review papers discussing transcriptional regulations and/or promoter classes in Gram positive bacteria? Thank you so much for your help!

08 February 2021 6,909 3 View

Flexibility of RNAseq?

When you use RNAseq I understand that it must follow certain conditions when you use it. One of them is the insertion of a polyA tail. The insertion of the polyA must include then...

05 February 2021 3,770 4 View

How do microbes tell the presence of an inorganic minaral in the soil?

Due to their ubiquitous nature, there is a tendency of the presence of microbes in a given mineral(s). For instance, if microorganisms that love the of pH less than 6 in the pH value, is isolated...

03 February 2021 4,630 10 View

Moving bacteria-like organisms in my HEK293T cell culture?

Hi everyone, I have been culturing HEK293T cells that have been engineered to overexpress the mechanosensitive protein Piezo1. However, I am finding it very difficult to keep them in culture -...

02 February 2021 7,892 4 View

David Rotter

To my knowing, the most widely used and accurate methods are HPLC (high performance liquid chromatography ), LC-MS (Liquid Chromatography Tandem Mass Spectrometry).

A pretty up to date summary should be in this book:

Eitenmiller, R. R., Landen Jr, W. O., & Ye, L. (2016). Vitamin analysis for the health and food sciences. CRC press.

Hope that helps!

Jorge Andrés Sánchez-Duque

The world of micronutrients still has many gaps, and the specific case of vitamin b12 is particularly complex given the clinical importance of its levels, which are low, but also high. In this sense, in complement to the debate question, I want to share with you the following manuscript detailing the aspects associated with high levels of vitamin b12.

Article Hipervitaminosis B12 una mirada desde la atención primaria