en Clinical Medicine Clinical Medicine گزارش کوتاه Short Communication <div style="text-align: justify;"> <div> <p><span style="font-size:16px;"><span style="font-family:Times New Roman;">Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a pandemic (1). Early diagnosis and testing of symptomatic individuals and asymptomatic carriers (2) remain essential since the latter group can transmit the virus (3,4). Current assays for SARS-CoV-2 detection are mostly based on quantitative real-time PCR (RT-qPCR)(5). However, cross-contamination remains a challenge in RT-qPCR assays. Here, we would like to share the most interesting route of sample contamination in SARS-CoV-2 molecular diagnosis laboratories and the necessity of personnel testing.</span></span><br> <span style="font-size:16px;"><span style="font-family:Times New Roman;">We set up our molecular diagnosis laboratory three months ago using RT-qPCR. We strictly adhered to biosafety guidelines to ensure personnel safety and avoid cross-contamination of samples. We use (i) two extraction negative controls (EXNC), (ii) one no template control for every 10 samples, and (iii) one negative control. Note that to minimize the probability of contamination, the positive control was prepared last, after each patient&rsquo;s sample was added to the corresponding tube.</span></span></p> </div> </div> <div style="text-align: justify;"></div><div style="text-align: justify;"></div> SARS-CoV-2, molecular diagnosis, Quantitative Real-time PCR, 350 351 http://journal.zums.ac.ir/browse.php?a_code=A-10-5681-1&slc_lang=en&sid=1 Vahid Kia vahidkiaa@shmu.ac.ir 5200319475328460088818 5200319475328460088818 Yes Dept. of Medical Biotechnology, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran Maryam Teimouri teimouri.m@shmu.ac.ir 5200319475328460088819 5200319475328460088819 No School of Paramedicine, Shahroud University of Medical Sciences, Shahroud, Iran Fatemeh Sadat Bitaraf bit.bio.sh@gmail.com 5200319475328460088820 5200319475328460088820 No Dept. of Medical Biotechnology, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran