Viral Transport Medium(VTM/UTM)
Viral Transport Medium
20 servings / box
Collection, storage and transportation of human nasopharyngeal virus samples
The virus sampling kit is based on Hank's solution. The solution contains inorganic salts, amino acids, and protein-stable ingredients. The virus sampling kit has a stable osmotic pressure, which provides a stable transport and storage environment for nasopharyngeal swab samples. Samples are sent to the laboratory for follow-up testing to determine whether the collected samples are infected with the virus.
|Sample tube||1 sampling tube with 3.5ml sampling solution||1 sampling tube with 3.5ml sampling solution|
Sampling tube: 100mmx16mm 120mmx16mm
sodium chloride: 0.8%,
potassium chloride: 0.04%,
calcium chloride: 0.014%,
Magnesium sulfate heptahydrate: 0.02%,
Disodium hydrogen phosphate heptahydrate: 0.012%,
potassium dihydrogen phosphate: 0.006%,
sodium bicarbonate: 0.035%,
phenol red sodium salt: 0.002%.
|Sampling swab||1 sampling swabs||2 sampling swabs|
1. In 2006, virus preservation solution was Hank's solution.
In 2010, upgrade to UTM, with a higher PCR test positive rate and shorter test time.
UTM is recommended by the World Health Organization and the National Influenza Center of China.
Based on Hank ’s, UTM adds BSA, HEPES, amino acids, glycerin and other ingredients, with higher PCR positive rate.
1.A type H3N2 virus (virus titer is greater than 1e6), diluted 10 times, 100 times, 1000 times and 10,000 times
with UTM and Hank ’s.
2. Refer to the temperature of the samples (cold or room temperature) and the time of inspection (within 24
hours) after sampling, the UTM and Hank's of different dilutions are stored at 4 ° C and 25 ° C for 24 hours.
3. CT values are detected with real-time PCR instrument
1. No matter whether it is stored at low temperature or room temperature, UTM has a lower CT value than
Hank ’s at different virus dilution, which means shorter detection time.
2. In the case of 10,000x dilution, Hank ’s cannot be detected. However, UTM can still be detected. That is,
UTM has a higher positive rate of PCR detection.
2.In real work, almost every laboratory will have a positive PCR test, but the virus cannot be isolated.
The reason is that virus isolation is performed after the positive PCR result, time difference is the main reason for this problem.
1. The A-type H1N1 virus and H3N2 virus suspensions (the virus titer is 1x106, which is equivalent to the
virus level while the actual sampling conditions are not good) are stored in UTM solution.
2. After storage at 2-8 ° C and room temperature for 24h and 48h, UTM solution with virus was inoculated
in MDCK cells and incubated to produce CPE (lesion response), and then incubated with fluorescein-labeled
3. The number of virus particles infected with MDCK cells was detected. That is, the number of green
fluorescent stove points in the figure below.
Regardless of the virus is stored in UTM at 2-8 ° C or room temperature, the virus can be isolated within
3.The virus sample collected in the swab can only be detected by PCR and separated from the virus if it is successfully released into the sampling solution.
The release rate of the swab greatly affected the positive rate of PCR detection and virus isolation.
In order to increase the swab release rate, we innovatively add specially treated glass elution beads to the sampling solution.
Experiments have shown that the sample release rate has increased 3 times.
The used sample collection tube should be placed on an oscillator.
The vortex generated is shaken to drive the elution beads to hit the sampling swab, so that the cells and virus particles adhered to the swab are released into the virus sampling solution.
The number of virus particles eluted into the sampling solution can be accurately calculated by using
immunofluorescence method and observing live fluorescent particles labeled with green fluorescent
protein (GFP) under the fluorescent inverted microscope.
The sample release rate has increased 3 times.
4.Mold contaminationafter sample collection is a problem for the laboratory to prepare sampling liquid or other brands of sampling tubes.
In order to inhibit bacteria in the early sampling solution, penicillin (inhibiting bacteria) and amphotericin B (inhibiting mold) are added.
Relatively, penicillin is still stable at normal temperature, while amphotericin B is stable only at -20 ° C. The activity of amphotericin B decreases rapidly at room temperature until it disappears.
That is the main reason why most of the sampling tubes cannot be stored at room temperature.
As a company specializing in cell culture and virus isolation, Yocon Biology replacespenicillin with stable gentamicin at room temperature.
Not only solves the problem of allergies to penicillin in some people, but also raises normal temperature Antibacterial effect of the stored sampling solution on bacteria.
The amphotericin Bwas replaced with a normal-temperature stable fungal antibiotic, which solved the problem of mold contamination after sampling and saved the sample solution at room temperature.