External validation of SARS-CoV-2 rapid tests Acro Biotech
The urgent need for reliable diagnostic tests in response to COVID-19 requires laboratories to have independent external validations to facilitate the choice of the best available rapid tests. Independent and robust post-market evaluations of COVID-19 tests allow confirmation of manufacturers’ performance claims. The basic measures for quantifying diagnostic test performance are sensitivity and specificity. Therefore, we are pleased to include in this section validations performed by external laboratories with Acro Biotech rapid tests where the agreement between stated technical specifications and those observed in real situations can be checked.
This retrospective study, conducted by Biomex Laboratories in Heldelberg (Germany) on freeze-dried swab samples from healthy and COVID-19 infected donors, is an observational study aimed at establishing the specificity and analytical/diagnostic sensitivity of the SARS-CoV-2 Rapid Antigen Test (REF: ISCO-ACO502).
Swabs from positive samples were collected during the infectious phase from patients infected with COVID-19, swabs from negative samples were collected from healthy donors. After collection, all swabs (dry swabs) were immediately stored at ≤-20°C. As a reference method, all samples were tested with an RT-PCR system.
The specificity of the rapid test for SARS-CoV-2 antigen calculated from the results of all samples was 100 %, the sensitivity calculated from the results of samples with a Ct value below 32 (103 samples) was 96 % (95 % CI: 90-99 %). As expected, sensitivity decreases when samples with a higher Ct value are included. Thus, when including all samples with a Ct value equal to or lower than 36 (137 samples) the sensitivity is estimated at 81 % (95 % CI 74-87 %).
- Systematic study, published in Diagnostics by researchers from UK and Canada, reviewing independent studies evaluating the performance of 42 rapid tests for serological testing of SARS-CoV-2. In this study the best Covid19 rapid tests were evaluated according to the accuracy criteria, finding a large variability in the sensitivity and specificity of the tests analyzed. We are proud to report that Acro Biotech, Inc. COVID-19 Rapid POC Test is among the best performing of the 42 rapid tests evaluated, with a sensitivity and specificity of 100%.
- Prospective study conducted at the Frederick National Laboratory for Cancer Research (FNLCR), a Federally Funded Research and Development Center (FFRDC) sponsored by the National Cancer Institute (NCI) or the Hemostasis Laboratory Branch, Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (CDC) in the United States. Each test was evaluated against “Panel 1,” “Panel 2,” or “Panel 3,” each of which includes frozen serum samples with antibodies to SARS-CoV-2 (n = 30) and frozen antibody negative serum plasma samples and anticoagulant citrate dextrose formula A (ACD-A) anticoagulant solution (ACD-A) (n = 80). Although ACD-A plasma may not be commonly used in clinical practice for serologic testing, ACD-A plasma samples were used here because these prepandemic samples were more readily acquired from blood banks. The size and composition of the panel were chosen to allow for laboratory-based evaluation and to provide reasonable estimates and confidence intervals for test performance in the context of limited sample availability. The sample size is comparable to a typical sample size used to support Emergency Use Authorization (EUA) by the FDA for tests of this type. Of note in this study, the presence of antibodies was confirmed in FNLCR using CDC-developed ELISAs (Pan-Ig, IgG and IgM) as well as an IgG receptor binding domain (RBD) ELISA, and the concordance of the “2019-nCoV IgG/IgM
Rapid Test Cassette(Whole Blood/Serum/Plasma)”. Positive samples were evaluated at dilutions of 1: 100, 1: 400, 1: 1600 and 1: 6400 by CDC in its Pan-Ig assay, its IgM assay and its IgG assay. Some samples were tested with additional dilutions. All samples that tested positive at a dilution greater than 1: 6400 were assigned a titer of 6400 because 1: 6400 was the highest dilution at which all positive samples in Panel 2 were evaluated.
Acro Biotech is a California-based rapid test manufacturer offering state-of-the-art products that comply with the ISO 13485:2016 CMDCAS standard. They have a wide range of rapid tests such as drug abuse tests, cardiac markers or infectious diseases. Innovation and marketing, with the aim of introducing new products on the market that make a difference, including the combination of digitalization and the ease of rapid tests.