Virus DNA/RNA Extraction Kit(Fast)

The  Extraction Kit is developed to extract high purity viral DNA/RNA from throat swabs utilizing a unique lysis buffer and new nanomagnetic beads, resulting in a very quick time to analysis.

Intended Use

For nucleic acid extraction, enrichment, purification, and other steps. The treated products are used for clinical in vitro detection.

Inspection Principle

This product utilizes the specific adsorption capacity of magnetic beads for nucleic acid in the environment of high ionization salt to enrich nucleic acid in the sample lysates. After washing for removing impurities, the enriched nucleic acid is released in the eluate to achieve the purpose of nucleic acid purification.

Main components

1. Each functional component of HMD3603 and HMD3613 has been packed in deep hole plate in preloading, Lysis buffer 300 μL/test, Wash buffer 1 500μL and Wash buffer 2 700 μL×2 per test, Magnetic beads 200 μL/test, and Eluate 50 μL/test.
2. HMD3503 put the corresponding amount of Lysis buffer (300 μL/test), Wash buffer 1 (500 μL/test), and Wash buffer 2 (1400 μL/test). Eluent (50 μL/test), Magnetic beads (200 μL/test) in different containers, and separate them into the deep well plate or other containers by the operator before use.
3. Reagent Specifications: Plate packaging
4.  

Bottle packaging:

Storage Condition and Validation Date

Store proteinase K and magnetic beads at 2℃-8℃, keep storage at 2℃-25℃ for the rest. Freezing can greatly reduce the performance of magnetic beads. Please avoid freezing during storage and transportation. This reagent is valid for 12 months under appropriate storage. Use the pre-loaded reagent as soon as possible after opening it.

Applicable Instruments

Allsheng Auto-Pure 32A automatic nucleic acid extractor and similar instruments.

Sample Requirements

1. This product is suitable for nucleic acid extraction of cells and pathogens from nasopharyngeal swabs, saliva, urine, plasma, serum, cell preservation fluid and other liquid samples.
2. Immediately after collection, samples should be placed into cell preservation solution that can be used for nucleic acid detection for fixation and preservation, and nucleic acid extraction should be carried out as soon as possible.
3. Nuclease can affect the performance of this product
4. Saliva sample: take more than 200μL saliva sample, if less than 200μL, please use all.
5. Dry swab sample: add 400μL PBS (sample storage solution with sample swab) to sample tube with swab head, vortex for 2min, then use 200μL supernatant after centrifugation at top speed
6. Wet swab sample: mix with high-speed vortex for 1min, absorb 200μL for use (if the liquid is less than 200μL, add appropriate amount of PBS or sample storage solution with the sampling swab, mix with vortex and centrifuge).
7. Other liquid samples: more than 200μL take 200μL, if less than 200μL, please use all.

Self-provided Materials

1. Automatic nucleic acid extraction instruction (For automatic extraction methods, this description takes HMD3603 and Allsheng Auto-Pure32A automatic nucleic acid extraction instrument as an example.
2. 96-well deep hole plate and magnetic rod sleeve (HMD3503 automatic extraction).
3. Magnetic rack (HMD3503 manual extraction).

Preparations

1. Please take out the buffer from the refrigerator, and use it till room temperature.
2. If there is a small amount of precipitation in the lysis buffer, please place it at room temperature or 37℃ and use it after the precipitation is fully dissolved.
3. Before use, magnetic beads must be shaken until there is no visible precipitation at the bottom before being used.

Operation Steps

HMD3603/HMD3613 automatic extraction

1. Unseal: take out the deep-hole plate from the packaging box, balance to room temperature, carefully tear off the sealing film, if there is liquid adhesion to the deep-hole plate sealing film and tube wall, throw the liquid to the bottom and then unseal.
2. Add sample: Add 200 μL sample and 50 μL protease to column 1/7 (HMD3603) or plate 1 (HMD3613), one sample for each well position. Note: please add sample within 20 minutes after opening.
3. Load in machine: set extraction procedures according to supplemental table. Put the deep-hole plate into the nucleic acid extraction instrument, insert the magnetic rod sleeve into the corresponding slot, and start the program. After the procedure was completed, the eluent was transferred to a centrifuge tube and the product was stored at -80℃. Discard waste according to standard procedures.

HMD3503 automatic extraction

1. Add samples: add samples in the order of Table 4.
2. Load in machine: Set extraction procedures in accordance with supplemental table. Put the deep-hole plate into the nucleic acid extraction instrument, insert the magnetic rod sleeve into the corresponding slot, and start the program. After the procedure was completed, the eluent in well 6 or 12 was transferred to a centrifuge tube and the product was stored at -80℃. Discard waste according to standard procedures.

Limitations of test methods

Automatic extraction of this product needs to be used together with an automatic nucleic acid extraction instrument. Manual extraction should be used together with a magnetic rack.

Precautions

1. This product is only for in vitro diagnostic use, not for human or animal internal and external use.
2. The extracted nucleic acid should be used for testing as soon as possible. If it is not tested immediately, the nucleic acid should be removed from the deep hole plate, placed in a container without nuclease, and stored at -20℃.
3. During the operation, please wear disposable gloves, disposable masks, and lab coats. Nuclease-free consumables are used to minimize RNase contamination. The lysis buffer and Wash buffer 1 contain guanidine isothiocyanate or guanidine hydrochloride, which will cause corrosion to skin and mucous membrane, If it is not carefully exposed to the eyes, Please rinse with plenty of water and seek medical advice.
4. Do not mix the waste liquid with bleach or acidic solution to avoid toxic volatile substances.

Performance

1. Reagent packaging should be intact and tidy.
2. Net content of each component: no less than marked amount.
3. Extraction yield: Nucleic acid purification for 100 μL~400 μL liquid sample, eluent yield is not less than 42 μL.
4. Nucleic acid recovery rate: nucleic acid purification is performed on the calibrated DNA samples, and the recovery rate is no less than 90%.
5. Purity of nucleic acid: Nucleic acid purification was carried out on the calibrated DNA sample, and the OD260/OD280 product was between 1.7 and 2.0.
6. In-batch precision: Ct value is obtained by amplification of extract using calibrated reference and fluorescent PCR reagent specified by the enterprise, with a repeatability CV of no more than 5%.
7. The purified nucleic acid can be detected by PCR and other molecular biology.

Eg： Extract 200μL with a density of 5×103 IU/mL COVID-19 pseudovirus throat swab sample, test with a COVID-19 detection kit. After 10 parallel experiments, results show that the detection rate is 100% and the reproducibility of the Ct value is good (Figure 1). RT-qPCR detection is performed on the extracted products from pharyngeal swabs of different concentrations of COVID-19 pseudovirus, and the results showed that the extraction ability of samples of different concentrations of COVID-19(5×101 IU/mL，5×102 IU/mL，5×103 IU/mL，5×104 IU/mL，5×105 IU/mL) is good and the differentiation degree is obvious (Figure 2). The logarithm of the Ct value of RT-qPCR and the number of pseudovirus is analyzed by linear regression. The results showed well linearity (Figure 3)

References

He H, Li R, Chen Y, et al. Integrated DNA and RNA extraction using magnetic beads from viral pathogens causing acute respiratory infections. Sci Rep. 2017; 7: 45199. Saiyed ZM, Ramchand CN, Telang SD. Isolation of genomic DNAusing magnetic nanoparticles as a solid phase support. J Phys Condens Matter. 2008; 20(20):204153.