No more concerns of denaturation!  The C10 enables us to process the samples collected from the same time simultaneously.

This time, we had an interview with assistant prof. Ms.Tomita who is working on the metabolomics basic research.

Interviewee:
Assistant Prof. Ms. Ryoko Tomita, Institute of Analytical Sciences, Faculty of Pharmaceutical Sciences, University of Fukuoka

BioChromato

Can you tell us about your research?

Ms. Tomita

We are conducting the fundamental research on the evaluation of the cultured cells state by metabolomics, and currently we are measuring amino acids in the cell culture medium as a target.

BioChromato

For what purpose do you concentrate in your research?

Ms. Tomita

Some low-molecular metabolites in cells such as amino acids have low concentrations, so they cannot be detected by LC-MS / MS. Therefore, in order to increase the concentration and make it detectable, the samples will be concentrated.

BioChromato

What kind of work needs to be done before concentrating?

Ms. Tomita

I use the 50 ml screw tube and the 10 ml screw-top test tube. For solvents I usually use water, a mixture of water and acetonitrile, and a mixture of water and methanol. The amount of the sample varies from less than 1 ml to even 150 ml. We divide it into 1ml – 20ml range according to the container sizes. For the liquid-liquid extraction, solvents such as chloroform or hexane are sometimes used, but there is no other equipment that can handle these solvents so your system is useful.  Both the main unit and the vacuum pump are installed in the draft. Some drugs may get affected by the heat, so we refrain to add too much heat. We usually apply about the room temperature of 25℃.

BioChromato

What kind of organic solvent and its capacity do you evaporate after extraction?

Ms. Tomita

A methanol solution or an acetonitrile solution of about 60% to 80%. 800 μL of each volume is evaporated using a 1.5 mL tube.

BioChromato

It seems that the sample contains water, so how much do you set the temperature at?

Ms. Tomita

We set it 50 ° C to evaporate as soon as possible. From our experiences free amino acids in samples do not get affected by this temperature.

BioChromato

Can you tell us the number of samples and the operation time when evaporating water, methanol plus water or acetonitrile?

Ms. Tomita

It takes several days for the whole experiment. Specifically, in order to measure the intracellular metabolite concentration over time, samples are collected approximately every 24 hours, 30 minutes for extraction, 4 to 6 samples once a day for evaporation which takes 2-3 hours. This process needs to be repeated about five times over several days.

BioChromato

So since the whole experiment takes several days, you must want to shorten the time required for each process. How was the process like before having the C10?

Ms. Tomita

Previously, I was using the nitrogen blowdown evaporator for drying up completely.  I was using the same container with the one I use now, but since I could process only 1 to 2 samples at a time, it took me a very long time to finish all the samples. As a result, I used to feel reluctant to carry the evaporation process as a sample pretreatment.

BioChromato

I see. Because our system recommends an oil-less diaphragm vacuum pump at low vacuum, it saved the labor for oil exchange. Do you mean this fact was also an important factor for selecting the product??

Ms. Tomita

No. That was an aluminum block type, and it allowed 9 samples to set.  However, the flow rate of nitrogen gas increases and that leads to the fast consumption of nitrogen. And it is left from several hours to half a day at room temperature while blowing, so there was a risk of sample denaturation. So 1-2 samples were made to dry in a short time even the device is designed for 9 evaporations at a time.

BioChromato

I see. The method was divided for 1-2 samples, and that was for reducing the risk of sample denaturation. That was why evaporating all the samples takes so long. So you don’t feel reluctant for evaporation now?

Ms. Tomita

Yes, even the water does not take much time to evaporate and I do not mind the consumption of nitrogen gas. I can work freely without any hesitation. We collect samples at a time and evaluate the fluctuation over time. With the previous method there could be temporal variations among samples in the process from extraction to evaporation, but the C10 is useful because we can process 4 to 6 samples simultaneously. It is good that I can concentrate the samples collected from the same time, at the same time and under the same conditions. We’ve been able to detect about 20 kinds of amino acids measured by LC-MS/MS after evaporation. Though we’ve changed the evaporation method, we don’t have any cases like samples become undetectable or the unknown peak appeared on the chromatogram.

BioChromato

Even the principle of the Smart Evaporator does not affect LC-MS / MS measurement, and it is a great honor to know that now you don’t feel reluctant to concentrate samples.  Can you tell us the impression when you found about the Smart Evaporator for the first time?.

Ms. Tomita

At first I found about you on brochures from agents and exhibitions at academic conferences.  I had a strong feeling that even the solution that contains water is hard to evaporate, but I felt it must be very convenient when I saw your description “Even DMSO solution can be evaporated”.  Originally only the single position model was available, so I thought that would not be used for my research. Then I heard that multiple position model launched. I consulted with other professors in the laboratory and decided to purchase one.

BioChromato

We believe that it is attractive for many researchers that this evaporates high boiling point solvents such as water and DMSO. Thank you for your valuable story.

Ms. Tomita

At first I found about you on brochures from agents and exhibitions at academic conferences.  I had a strong feeling that even the solution that contains water is hard to evaporate, but I felt it must be very convenient when I saw your description “Even DMSO solution can be evaporated”.  Originally only the single position model was available, so I thought that would not be used for my research. Then I heard that multiple position model launched. I consulted with other professors in the laboratory and decided to purchase one.

Summary

Assistant prof. Ms.Tomita needed to raise the concentration when detecting amino acids as a target by LC-MS / MS, and had desired the most to avoid the denaturation of samples during concentration in order to evaluate the sample variation over a time. Up to now, she needed to repeat the process with 1-2 samples for some times when she actually needs to evaporate 4 to 6. She was feeling reluctant to do evaporation because it took her long. To cope with such a problem, the Smart Evaporator C10 is capable to concentrate samples collected from the same time, at the same time and under the same condition. Even if it contains the water, it will be processed quickly, and she became able to prevent the sample denaturation.
In addition, even if the concentration method was changed, she didn’t have any cases the samples become undetectable by LC-MS / MS or no unknown peak appeared. This becomes a good example showing us that the improvement of concentration efficiency was accomplished by the C10.
(Interviewer: Kikuchi)

■Interested in what Smart Evaporator is? You can learn from here!

■Product details of Smart Evaporator C10 (10 channel evaporator)

 

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