The type of samples that you collect for your study is likely to be dictated by the diagnostic test(s) that you plan to use. As well as the type of sample, there are a number of other things to consider when sampling, such as patient and healthcare worker health and safety, and safe and appropriate packaging and transportation to the laboratory. The following resource links aim to provide information that can be adapted to your country and your project. It is important to remember, especially with health and safety, to always comply with your country’s guidelines.
What type of sample should I use?
The type of sample required depends on what you wish to test. If you are undertaking a test that requires nucleic acid, nasal or oral swabs are generally the best option, as the greatest number of virus particles are found in the lungs and upper respiratory tract. If you are looking to do antibody tests, you will need blood samples.
This publication has compared the RT-qPCR detection of SARS-CoV-2 in different types of clinical sample.
How to collect samples
Nasal and/or oral Swabs
Choosing the best swab material
Choosing a viral transfer medium
It is important to use the correct media to collect samples. Storing samples in media will preserve any viral particles better than a dry swab and viral transfer media should always be used, never bacterial transfer media.
Choosing the best swab location
Swab sampling technique
It is important that anyone taking a sample from a potentially COVID-19 positive patient be protected from potential infection by wearing PPE. Please follow the link to the Health and safety page/area
YouTube instructional video - Performing a Nasopharyngeal and Oropharyngeal Swab.
Instructional video – Performing swab sample collection
Collecting blood for antibody tests
Whilst potential exposure to SARS-CoV-2 is accepted to be lower for blood sampling compared to swabs, it is still important to follow the same health and safety principles. Health care workers should still use the appropriate PPE when taking samples from patients.
The WHO guidelines provide recommended steps for safe phlebotomy and reiterate accepted principles for drawing, collecting blood and transporting blood to laboratories/blood banks.