Qiagen RNA extraction kits use AVL buffer. AVL buffer has 50-70% guanidinium isothiocyanate according to their safety data sheet. Their website doesn’t let you link directly to the safety data sheet as the url expires after some time; so I’ve saved it in (the amazing) internet archive: https://web.archive.org/web/20200414164736/https://sds.qiagen.com/ehswww/QIAGENwww/result/report.jsp?P_LANGU=E&P_SYS=4&P_SSN=42571&P_REP=00000000000000000090&P_RES=756783
Hazardous ingredients
| Chemical Name | CAS-No. | Concentration (% w/w) |
| guanidinium thiocyanate | 593-84-0 | = 50 – < 70 |
It’s important to note that they don’t share what else is in the AVL buffer. And that there’s research to show this buffer may be insufficient to inactivate some viruses: https://jcm.asm.org/content/53/10/3148 “Buffer AVL Alone Does Not Inactivate Ebola Virus in a Representative Clinical Sample Type”
alexanderjamesphillips 