In brief, we do not recommend this activity.
Schools must follow the policies and procedures in their jurisdiction. The technique described uses a salt water solution being gargled and then spat into a cup to collect cheek cells.
In NSW government schools, science experiments using human blood, blood products, and human tissue, e.g. cheek cells must not be conducted. Further information is available from the NSW Department of Education’s Chemical Safety in Schools Package (CSIS) online (DoE intranet) to all staff in all government schools in NSW. Go to Section 3.2.6 for the Safe use of biological materials/organisms/tissues.
Other sectors/states/territories may have different policies, such as being subject to a risk assessment. However human tissue and body fluids have the potential to transmit infectious diseases. See our previous Q&A on Using body fluids in science for more details on this topic.
Science ASSIST does not recommend the use of human tissue or body fluids in school science practical classes due to the risk of disease transmission.
‘Using body fluids in science’, Science ASSIST Q&A, Science ASSIST website, https://assist.asta.edu.au/question/3273/using-body-fluids-science (22 October 2015)
NSW Department of Education and Communities ‘Chemical Safety in Schools (CSIS)’ resource package. NSW DoE website http://www.dec.nsw.gov.au/ DoE Intranet, login required.