感染prion蛋白相關疾病之風險, e.g. Creutzfeld–Jakob disease (CJD)
其他缺點包括: 品管無法有效監控，來源限制, ...
- Lack of regulatory control.
- Impossible to trace donor source.
- Quality cannot be checked during transportation.
- Urine sources cannot be validated.
- Decontamination may denature proteins.
- Cross-contamination cannot be avoided.
- Poor quality control.
- Limited source.
