Q-Dots or other high yield fluorophore that exite at ~254nm and emit at ~300nm?

More Yoram Gerchman's questions See All

What is the biological importance of alkaline phosphatase in milk?

Greetings all As you might know raw milk has an alkaline phosphatase activity, and indeed this activity is used for pasteurization quality control. The question I am wondering about is, what is...

05 June 2019 4,434 1 View

Extraction of Heme A, Heme B and Heme O?

Greetings I am looking for a trusted protocol for extraction of Heme A, Heme B and Heme O, to be used as standards in HPLC analysis. Alternatively if you know of a commercial source also...

04 May 2019 5,446 2 View

Plasmid for constitutive expression of gfp in Bacillus subtilis?

Greetings Does anyone have , and is willing to sent me, a plasmid suitable for constitutive expression of gfp in Bacillus subtilis? Many thanks Yoram

03 April 2019 1,471 1 View

Illuminating a sample with 2 wavelength simulteneously?

Greetings I am looking for an optical setup that will enable me to illuminate a single sample with two different wavelength in the UV range simultaneously. I though about placing 2 monochromators...

10 November 2018 1,529 0 View

What are the carbon 'species' in traeted wastewater? A good model compound for such?

Greetings all As wastewater get biologically treated carbon is removed, but obviously not all carbon species are removed, since some are more easily consumed by the bacteria doing the treatment....

10 November 2018 6,225 2 View

Origin of 220nm absorbance peak of free amino acids?

Greetings I am trying to find out what is the origin of the 220nm absorbance peak of free amino acids? It is usually attributed to peptide bond but I find it also in single aa... Yoram

05 June 2018 6,591 3 View

Why do particles concentrated in water droplet edge?

Greeting. I have noticed a pattern and wonder what is the reason. When ever I have suspension of particles in water droplet, be it bacteria or abiotic they seem to concentrate in the edge of the...

04 May 2018 10,029 1 View

Can I connect HP1047A RI detector to Agilent 1200 HPLC system?

Greetings We need to buy an RI detector for our Agilent 1200 HPLC system (connected to a computer running ChemStation). Given the high price of new detector I thought about buying a used one....

09 October 2017 7,137 10 View

Fluorescent dye that bind to dsRNA but not ssRNA?

Greetings all. We are looking into following the kinetics of short dsRNA melting and about using a dye that will bind differently to dsRNA and ssRNA. Any idea for such a dye? Or to another simple...

06 July 2017 6,650 1 View

Quantifying UV irradiation of different lamps by UV sensor?

Greetings I am trying to quantify UV irradiation form different UV lamps buy using UV sensor. The problem is the response curve of the sensor is different for different wavelength (as it is often...

05 June 2017 7,322 4 View

Is There Any Feasible Method To Test Fluorescent Compounds Other Than Fluorescence Spectrometers ??

Is There Any Feasible Method To Test The Efficiency Of Fluorescent Compounds Other Than UV Spectrometers ? Suggestions Would Be Appreciated !

02 March 2021 5,785 3 View

How to accurately quantify chitin?

Hi all, I have been working on the quantification of chitin in insect samples and feed for a while but I can notice that the quantification methods (e.g. exposure to HCl, NaOH, and weighing sample...

01 March 2021 1,843 2 View

Can someone suggest a way to prepare slides to observe under confocal microscope for observing fluorescent tagged proteins??

I am growing the cells on coverslips and transfecting the fluorescent tagged protein directly on them. Then i want to observe these cells under confocal microscope. Currently i am just using...

01 March 2021 6,142 3 View

Why does intensity drops as concentration increases?

Is there any reason for decrease in fluorescence emission intensity of HSA,BSA when increase the concentration ?

28 February 2021 3,653 4 View

How to compare 2 samples recruited with different sampling methods?

If I want to compare characteristics of 2 groups of patients, one group is recruited from a random sample of the general public while another group is from a sample with a fixed gender (male to...

26 February 2021 3,526 3 View

Quantifying leaking DNA from bacteria - what's the secret?

Hi, all! I need to determine if my treatment causes membrane damage in bacteria (S. aureus and E. cloacae), but I cannot use a fluorescent probe such as PI and similar ones because my compound is...

24 February 2021 2,006 2 View

Do you consider undergoing a structure literature review / Meta analysis and getting numerical findings sort of quantitative method?

I am looking for a classification of the research methods included in literature review papers or Meta analysis ones .

22 February 2021 1,131 4 View

Did anyone perform CD107a degranulation assay without the use of inhibitors like monensin?

I am planning to perform a degranulation assay using CD107a antibody. Some resources suggest to use inhibitors like monensin to inhibit the intracellular traficking and acidification of the...

21 February 2021 6,260 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

Interpretation of a fluorescence Emission spectrum ?

Hello, i work with a spectrometer which only render the fluorescence emission spectrum. Until now i just found how to interpret an exitation- and emission spectrum together to generate deeper...

20 February 2021 1,291 3 View

Ofir Tal

Sounds like Tyrosines abs and emission. Although I'm not sure regarding the q.y..

Fabrizio Messina

Tyrosine QY is very low. PTP is indeed a good suggestion (you can solve it in methanol or ethanol in reasonable concentration). If 350 nm emission still works, another alternative is 2,5-Diphenyloxazole..