FAQ

FAQ

  • [General] Poor Results, RCF and Poor Migration

    A :


     

  • [General] How Lateral Flow Immunoaasay Works

    A :


     

  • [Blood] I would like to ask you whether the blood for sample can be added with citrate or EDTA.

    A :

    Either EDTA or citrate can be added to blood samples. 

  • [Blood] If I add dilution buffer before the complete absorption of blood sample onto membrane what could it happen?

    A :

    Sensitivity could be decreased due to the reaction between sample dilution buffer and blood, unless sample loading is performed after complete absorbance of blood sample in the absorbance window. 

  • [Blood] Can I use serum or plasma (because of the better migration) for the test?

    A :

    Yes, you can use either serum or plasma 

  • [General] It seems that the sample buffer flowed alright on the membrane, but neither T line nor C line appears.

    A :

    (1) Please check if you use the buffer packaged with the device in same kit box.

    In the case of using the sample buffer provided from other company, the line will not appear. 

    In the case of using products of various companies, you have to use the same buffer provided by same kit. If you use other company’s buffer you can not expect the reliable test result. 

    Because each company has own optimized condition for buffer.





    (2) Please check if red color conjugates have been migrated by checking the device window.

    If red color conjugates have not been migrated, 

    it suggests that sample migration has been failed due to less volume of sample. So add more sample for the full migration. If the colorless solution has been migrated, 

    it suggests that over volume of sample was applied. Try test again by following the insert manual.

  • [General] Why the diagnosis should be tested as soon as possible after the opening of a foil pouch?

    A :

     


    Moisture (from air) could affect the test result. Once you open a pouch please continue the test. Do NOT allow the device to expose to air for long time. 

    It is necessary to check the duration of a pouch unsealed, if the test result is unclear. 


    The lateral-flow based immunochromatography utilizes the antigen-antibody interaction after absorbing the antibody protein against the virus in the specimen on the nitrocellulose membrane. 

    Once the moisture existed in the air is absorbed into the porosity structure of nitrocellulose membrane, the antigen in the urine could not interact properly with the antibody. 

    It is best to perform the test within 10 minutes after the opening of a pouch and it is recommended not to use device that is unsealed for a long time to obtain reliable results.

  • [General] What about the stability and shelf-life of SensPERT products?

    A :

    The shelf-life is 24 months (see ‘product insert’) at 4°C ~ 25°C (39.2°F ~ 77°F).
    Usually, products can be stored at room temperature. In tropical countries above 30°C, we recommend products should be kept in refrigerating condition (4°C/39.2°F). When you use the products stored in a refrigerator, you place the products at room temperature and wait about 15 ~ 30 minutes until the temperature of product reaches at the room temperature to obtain the best result. 

  • [General] What is different between ELISA and Rapid test?

    A :


     

  • [Blood] I can’t read correct result because of red test window.

    A :

    When you use whole blood as a specimen not serum/plasma, please use EDTA-tube to preventing blood clotting and hemolysis. Hemolyzed blood (or partially hemolyzed blood) causes strong background that give difficulty in reading.

    If you use serum/plasma, it will make you much easier reading less background with vivid signal.
  • [General] If you have faint positive line, is it positive or negative?

    A :

    As you know rapid test is based on the lateral immunochromatograpy technology and positive means that target molecules (antigen or antibody) is detected by double sandwich method using detector and capture. Rapid test is a qualitative test and tells YES (positive) or NO (negative). Appearing of test line regardless of the intensity of line (faint, medium intensity or strong intensity) should be determined as a positive. As long as any intensity of T line considered as a positive.

    No test is 100% accurate at all times and under all conditions; therefore, all test results should be interpreted in light of the patient’s health and prior likelihood of infection. 

  • [General] The test result was negative in 10 minutes, but later the test line showed up very weak purple color. Is it positive result?

    A :

    We recommend the test results should be interpreted within 10 minutes. Sometimes non-specific binding after 10 minutes may cause false test line due to the characteristics of lateral-flow technology and please disregard the results after 10 minutes. In case of low titer sample, you may see very weak line within 10 minutes. However in such case, you need to make decision based on the comprehensive information including clinical symptoms, history, available test results and other information. 

VetAll Laboratories
#B-305 Samsong Techno Valley, 140 Tongil-ro, Deogyang-gu, Goyang-si, Gyeonggi-do, 10594, Korea
TEL : +82-2-2219-3459 | FAX : +82-2-2219-3457 | E-mail : leonardo@vetall.com

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