￭ INVBIO saliva alcohol screening test kit detect alcohol presence in saliva. Therefore, directly dipping the strip into alcohol alone will not provide you with an accurate reading.
￭ It is very important that the test be read at exactly two minutes, The result you read 2 minutes after saturation with saliva is the accurate test result.
￭ Do not place anything in mouth for at least 10 minutes prior to testing!
SPECIMEN COLLECTION AND PREPARATION
￭ Nothing should be placed into the mouth of the subject for at least 10 minutes prior to saliva collection. This includes food, drink, tobacco products or other materials.
￭ Saliva specimen can be collected in a sputum cup or a clean container, or directly applied to the reaction pad of the test strip.
￭ Open the foil package and remove the test strip.
￭ Saturate the reactive pad by dipping the reaction pad into the saliva specimen collected in a cup, or saturate the reactive pad on the end of stick with saliva in mouth for 10 seconds, shake off the excess saliva.
￭ Immediately start timer and at exactly 2 minutes, compare the reactive pad with the provided colored chart.
Results after more than 2 minutes may be not accurate.
INTERPRETATION OF RESULTS:
￭ Negative: Almost no color change by comparing with the background. The negative result indicates that the BAC is less than 0.02%.
￭ Positive: A distinct color developed all over the pad. The positive result indicates that the BAC is 0.02% or higher.
￭ Invalid: The test should be considered invalid If only the edge of the reactive pad turned color that might be ascribed to insufficient sampling.
- Package Dimensions : 13.46 x 6.35 x 2.79 cm; 72.57 Grams
- Date First Available : 10 January 2020
- Manufacturer : INVBIO
- ASIN : B07VRKBTDZ
- Manufacturer : INVBIO
- Item Weight : 72.6 g
- Net Quantity : 10.00 Count
Rapid diagnostic tests based on antigen detection
One type of rapid diagnostic test (RDT) detects the presence of viral proteins (antigens) expressed by the COVID-19 virus in a sample from the respiratory tract of a person. If the target antigen is present in sufficient concentrations in the sample, it will bind to specific antibodies fixed to a paper strip enclosed in a plastic casing and generate a visually detectable signal, typically within 30 minutes. The antigen(s) detected are expressed only when the virus is actively replicating; therefore, such tests are best used to identify acute or early infection.
How well the tests work depends on several factors, including the time from onset of illness, the concentration of virus in the specimen, the quality of the specimen collected from a person and how it is processed, and the precise formulation of the reagents in the test kits. Based on experience with antigen-based RDTs for other respiratory diseases such as influenza, in which affected patients have comparable concentrations of influenza virus in respiratory samples as seen in COVID-19, the sensitivity of these tests might be expected to vary from 34% to 80%.1
Based on this information, half or more of COVID-19 infected patients might be missed by such tests, depending on the group of patients tested. These assumptions urgently require further study to understand whether they are accurate.
Additionally, false-positive results – that is, a test showing that a person is infected when they are not – could occur if the antibodies on the test strip also recognize antigens of viruses other than COVID-19, such as from human coronaviruses that cause the common cold. If any of the antigen detection tests that are under development or commercialized demonstrate adequate performance, they could potentially be used as triage tests to rapidly identify patients who are very likely to have COVID-19, reducing or eliminating the need for expensive molecular confirmatory testing.
With the limited data now available, WHO does not currently recommend the use of antigen-detecting rapid diagnostic tests for patient care, although research into their performance and potential diagnostic utility is highly encouraged.
Rapid diagnostic tests based on host antibody detection
There is another, more common type of rapid diagnostic test marketed for COVID-19; a test that detects the presence of antibodies in the blood of people believed to have been infected with COVID-19.2-5 Antibodies are produced over days to weeks after infection with the virus. The strength of antibody response depends on several factors, including age, nutritional status, severity of disease, and certain medications or infections like HIV that suppress the immune system.6-8 In some people with COVID-19, disease confirmed by molecular testing (e.g. reverse transcription polymerase chain reaction: RT-PCR), weak, late or absent antibody responses have been reported.6,7,9 Studies suggest that the majority of patients develop antibody response only in the second week after onset of symptoms.
This means that a diagnosis of COVID-19 infection based on antibody response will often only be possible in the recovery phase, when many of the opportunities for clinical intervention or interruption of disease transmission have already passed. Antibody detection tests targeting COVID-19 may also cross-react with other pathogens, including other human coronaviruses and give false-positive results. Lastly, there has been discussion about whether RDTs detecting antibodies could predict whether an individual was immune to reinfection with the COVID-19 virus. There is no evidence to date to support this.
Tests to detect antibody responses to COVID-19 in the population will be critical to support the development of vaccines, and to add to our understanding of the extent of infection among people who are not identified through active case finding and surveillance efforts, the attack rate in the population, and the infection fatality rate. For clinical diagnosis, however, such tests have limited utility because they cannot quickly diagnose acute infection to inform actions needed to determine the course of treatment. Some clinicians have used these tests for antibody responses to make a presumptive diagnosis of recent COVID-19 disease in cases where molecular testing was negative but where there was a strong epidemiological link to COVID-19 infection and paired blood samples (acute and convalescent) showing rising antibody levels.
- Bruning AHL, Leeflang MMG, Vos JMBW, Spijker R, de Jong MD, Wolthers KC, et al. Rapid Tests for Influenza, Respiratory Syncytial Virus, and Other Respiratory Viruses: A Systematic Review and Meta-analysis. Clin Infect Dis [Internet]. 2017 Sep 15 [cited 2020 Apr 1];65(6):1026–32. Available from:
- Liu Y, Liu Y, Diao B, Ren Feifei, et al. Diagnostic indexes of a rapid IgG/IgM combined antibody test for SARS-CoV-2. medxriv [Internet]. 2020;
- Zhang P, Gao Q, Wang T, Ke Y, et al. Evaluation of recombinant nucleocapsid and spice protein serological diagnosis of novel coronavirus disease 2019 (COVID-19). medxriv [Internet]. 2020; Available from:
- Pan Y, Li X, Yang G, Fan J, et al. Serological immunochromatographic approach in diagnosis with SARS-CoV-2 infected COVID-19 patients.
- Zhao J, Yuan Q, Wang H, Liu W, Liao X, Su Y, et al. Antibody responses to SARS-CoV-2 in patients of novel coronavirus disease 2019. medxriv [Internet]. 2020; Available from: https://www.medrxiv.org/content/10.1101/2020.03.02.20030189v1.full.pdf
- Okba N.M.A, Muller M.A., Li W, Wang C, et al. SARS-COV-2 specific antibody responses in COVID-19 patients. medxriv [Internet]. 2020
- Gorse GJ, Donovan MM, Patel GB. Antibodies to coronaviruses are higher in older compared with younger adults and binding antibodies are more sensitive than neutralizing antibodies identifying coronavirus-associated illnesses. Journal of medical virology.
- Lin D, Liu L, Zhang M, Hu Y, et al. Evaluation of serological tests in the diagnosis of 2019 novel coronavirus (SARS-CoV-2) infections during the COVID-19 outbreak. medxriv [Internet]. 2020; Available from:
- Wölfel R, Corman V, Guggemos W, Seilmaier M, Mueller M, Niemeyer D, et al. Virological assessment of hospitalized patients with COVID-2019. Nature [Internet]. 2020; Available from:
- Lou B, Li T, Zheng S, Su Y, Li Z, Liu W, et al. Serology characteristics of SARS-CoV-2 infection since the exposure and post symptoms onset. medxriv [Internet]. 2020; Available from:
- Liu W, Liu L, Kou G, Zheng Y, et al. Evaluation of nucleocapsid and spike protein-based ELISAs for detecting antibodies against SARS-CoV-2. medxriv [Internet]. 2020; Available from:
- Zhang W, Du R, Li B, Zheng X, et al. Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes. Emerging microbes and infections. 2020; 9(1):386-389.
- Zhou P, Yang XL, Wang X, Hu B, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. 2020 Mar;579(7798):270-273. doi: 10.1038/s41586-020-2012-7. Epub 2020 Feb 3.
- Wang N, Li SY, Yang XL, et al. Serological Evidence of Bat SARS-Related Coronavirus Infection in Humans, China. Virol Sin. 2018;33(1):104–107.
- Che X, Qiu L, Liao Z, Wang Y, et al. Antigenic cross-reactivity between severe acute respiratory syndrome-associated coronavirus and human coronaviruses 229E and OC43. The Journal of Infectious Diseases, Volume 191, Issue 12, 15 June 2005, Pages 2033–2037,