Why is the Hoechst 33258 dye for DNA quantification using jasco fluorometer giving me no stable reading but goes up and down?

More Shaimaa Hassan's questions See All

Negative charge nanoparticles cellular internalization versus positive ones

is negatively charged NPs preffered as vector for DNA than cationic one is it targeting to liver

04 May 2016 6,488 2 View

What steps should I take if my tissue sample for RT PCR becomes contaminated with formaline?

I take liver samples from rats to perform RNA extraction and real time PCR but these livers immersed in formaline for one hour i wash it with saline so i want to ask what is the effect of...

06 July 2015 1,755 5 View

How can I stop the aggregation of zein nanoparticles in treatment medium after treatment to cells?

zein nanoparticle tend to aggregate and coagglutinate when i added it to DMEM media to treat cellsI use tween80 as surfactant \ pluronicF86.can I incubate the cells with nanoparticle dissolved in...

04 May 2015 2,168 3 View

How can I overcome nanoparticle aggregation in dmem tissue culture mediation ?

my nanoparticle is aggregated in dmem during tissue culture how can i overcome this problem?if i can incubate my nano with cells for certain time till uptaking some of my nano without media then...

04 May 2015 8,655 2 View

Why did I get A260/A280 above two after alkali lysis method for DNA plasmid extraction?

I did alkali lysis of my bacteria and I got DNA concentration of 4000ng/µL, A260/A280 = 2.2 and A260/A230 of about 1.9 - what would be the expected contaminants and what shall I do?

10 November 2014 9,257 7 View

How can I use ethidium bromide to measure DNA concentration fluorimetry?

I want a protocol to measure DNA concentration fluorimetry using ethidium bromide dye.

05 June 2014 2,062 12 View

What is the difference between phenol:chloroform:IAA of pH 6.7 and pH 8?

There are 2 phenol: choloroform: isoamylalcohol on market one has pH 6.7 and the other a pH of 8. What's difference between them and which is better for DNA extraction?

01 February 2014 4,915 3 View

Can I use vancomycin rather than kanamycin for bacteria contain pEGFP-C3?

or any antibiotic rather than Kanamycin as it's not available

01 February 2014 4,132 3 View

What is an average yield of PCR product for human gene?

PCR product size 1.2 kb optimum yield after 30 cycle 20 ul reaction

31 December 2013 3,644 3 View

How many PCR runs are sufficient to create 1 mg your target DNA fragment?

I need 1mg DNA sample could be synthesized by how many PCR runs?

10 November 2013 9,403 13 View

Are there instances where molecules with larger molecular weights exhibit greater mobility than those with smaller molecular weights?

Hi, I know that low molecular weight (MW) molecules generally tend to have higher mobility, while high molecular weight molecules tend to have lower mobility. However, in my experimental...

06 August 2024 1,495 2 View

Weak DAPI staining after immunohistochemistry - how to improve?

After immunohistochemistry of previously fixed in PFA and EtOH and then frozen 20 μm sections of zebrafish brain, DAPI staining is very weak (right) compared to the same sections stained without...

05 August 2024 9,637 2 View

For an in-vitro drug release study, what molecular weight cut-off (MWCO) dialysis bag is required for a 117 kDa protein?

kindly reply me. Thanking you in advance.

05 August 2024 7,727 4 View

How to isolate lymphocytes from mouse spleen?

I have tried several times to isolate lymphocytes from mouse spleen, but all attempts have been unsuccessful. I tried most available protocols. I used different dissociation media (HBSS with Ca...

04 August 2024 9,913 7 View

How to start a Molecular Dynamics Simulation?

Is it possible to conduct a molecular dynamics simulation to see the effects of a specific carbohydrate on the structure of lipids (e.g., micelle structure)? I am a beginner in this field and plan...

03 August 2024 3,371 3 View

Which will be the best software for the Hydration shell analysis with molecular dynamics?

I am using a windows system, what software I should use for hydration shell analysis with molecular dynamics?

02 August 2024 3,143 4 View

Can anyone provide me with molecular docking softwares/ websites?

Molecular docking software/ websites?

02 August 2024 8,704 7 View

Do some Staphylococcus aureus strains have in vitro antimycobacterial activity ?

Some Staphylococcus aureus strains Inhibit the growth of Mycobacteria in Mueller Hinton Agar medium containing 10% OADC. Do some Staphylococcus aureus strains have in vitro antimycobacterial activity?

29 July 2024 10,023 2 View

How to restart MD without using checkpint file in GROMACS?

Dear All Gromacs User I would like to restart MD without using checkpint .cpt files? I heard there is a way for acheiveing this. Any input and sugegstions are most welcome. Thanking You Budheswar

29 July 2024 3,084 8 View

Is it necessary to attach fluorophore at 3' end in MIC RT PCR machine for Dual hybridization Probe designed especially for genotyping assay?

I designed 2 dual hybridization probes for my single SNP. where I attach my fluorophore 5'-FAM-nnnn-BHQ1-3', and 5'-HEX-nnnnnn-BHQ2-3'. I need to run it on the MIC RT PCR machine by Biomolecular...

28 July 2024 5,658 0 View

Hayder Obayes Hashim

well there are several reasons such as

1- if your dna sample have a large particles in this case centrifuge your sample (12000 g) and take the supernatant to measure

2- check your device may be it need a calibration or fixing

3- the input voltage can led to this too.

check these and there more .

Shaimaa Hassan

Dr hayder thanks for ur answer but i wanna tell u that I use NaCl & Tris &edeta of normal analytical grade not molecular biology grade could it affect the result or no?