Recently, xiaobian found that the sample pretreatment method stipulated by the NATIONAL standard is mostly nitrogen blowing and rotary steaming, while the vacuum centrifugal concentrator tried by the laboratory failed to go in?
Vacuum centrifugal concentrator is used to reduce the boiling point of solvent by vacuuming, vacuuming of vacuum pump and/or with cold trap to collect the evaporative vapor in time to complete the purpose of removing solvent and drying/concentrating samples. Because of continuous vacuumization, the boiling point of the solvent under vacuum conditions is reduced, and the sample temperature will be reduced, which can effectively ensure the activity of the sample; A certain centrifugal force will keep the sample at the bottom of the container, almost no loss; And can handle a lot of samples at the same time, small series of feeling than nitrogen blowing, steam, etc., on the sample processing capacity, ensure the sample activity, concentration efficiency are much stronger, after the user tries to reflect is very good, estimate or know less people? Many of the previous publicity emphasized freeze-drying, coupled with the national standard recommended rotary evaporation and nitrogen blower and other factors, so the vacuum centrifugal concentration appears low-key.
Nitrogen blowing is concentrated to some volatile solvents such as low boiling point ethanol at room temperature and pressure; Vacuum centrifuge concentrator can achieve solvent concentration by vacuum control for medium, high and low boiling point solvents. From my own understanding of this instrument, I think it is a good instrument, which can ensure the sample activity, and several times faster than freeze-drying. Compared with rotary evaporation and nitrogen blowing instrument, the sample volume is much larger. And also trust the software and data of professional manufacturers, to optimize the experimental scheme is very helpful!!
Vacuum centrifugal concentration meter on the design to use "control vacuum" key characteristics, there is not much to limit sample weight, which is better than a feature of the advantages of freeze drying, freeze drying need sample thickness is 1 cm, otherwise the lyophilization process will be slower), cheng fang sample container is actually placed on centrifugal rotor of the centrifugal vacuum concentration meter host, The rotor has a certain tilt Angle, so considering that the liquid level may flow out of a certain slope after the tilt, as long as it is not too full, enough to fill about 95%. Concentration meter is not the same as the size, the distribution of vacuum pump is not the same, any cold trap, host is not the same as the heating temperature, different set vacuum will affect the efficiency of enrichment, for example, use common enrichment apparatus enrichment nucleic acid in ethanol, enrichment, 70 ml about half an hour, if large infrared heating machine, also is a few minutes.
From the user's point of view, is to hope to clearly know the progress of the experiment, the panel display parameters, it is very convenient to optimize and adjust the experimental scheme;
Vacuum concentration is the key to the control of vacuum, ---- with a good pump, no control function on the pump a strong pumping, temperature drop too low lead to sample evaporation into sublimation, into freeze-drying, then the rate is absolutely slow down; With a pump, high temperature is easy to cause the samples, so the vacuum control absolutely necessary, in view of the instrument panel display data to adjust the Settings again vacuum and heating temperature, the sample handling up absolutely effective, so I'm more inclined to customize pump to compose a concentrated system, rather than buy don't brand enrichment system of the built-in pump, Built-in pump system although initially selected instrument can save snacks, but do experiments have a situation in the future, in what isn't very convenient for the pump, and a few manufacturer of vacuum centrifugal enrichment system of vacuum control function or not, or is not standard, or according to real data is not comprehensive, then can keep on the centrifugal speed, rotor on make up, looked very tough to get parameters, But it ignores the importance of a substantial vacuum.
