Skip to content
Login Register

#human samples

2 public questions tagged with this topic.

Animal Tissue Culture 2

The concept that all human samples are potentially infectious is called:

Universal precautions, now incorporated into Standard Precautions, embodies the principle that all human blood, body fluids except sweat, unfixed tissues, organs, and cell cultures should be regarded as infectious regardless of donor history or test results. Concept formalized by CDC in 1987 during HIV epidemic to protect healthcare and laboratory workers from occupational transmission. Rationale is that serological window periods, asymptomatic carriers, and unknown agents prevent absolute assurance of safety. Implementation requires barrier protection including gloves, laboratory coats, face masks and goggles when splashing anticipated, hand hygiene after glove removal, prohibition of mouth pipetting, safe handling and disposal of sharps in puncture-resistant containers, decontamination of work surfaces with EPA-approved disinfectants, use of biosafety cabinets for manipulations that may create aerosols, and prompt reporting of exposures. Training, medical surveillance, and availability of post-exposure prophylaxis complete program. This doctrine justifies treating routine cell culture as BSL-2 and underpins OSHA Bloodborne Pathogens Standard 29 CFR 1910.1030.

Ref: CDC Universal Precautions for Preventing Transmission of Bloodborne Infections, MMWR 1988; OSHA 29 CFR 1910.1030. https://www.cdc.gov/mmwr

View Details
Animal Tissue Culture 2

All unfixed human tissues and cells should be handled using:

Unfixed human tissues, blood, body fluids and all primary or continuous human cell lines must be manipulated under Biosafety Level 2 as stipulated by CDC/NIH Biosafety in Microbiological and Biomedical Laboratories. This requirement originates from unavoidable risk of bloodborne pathogens including HIV, HBV, HCV, HTLV and emerging viruses that may be present without clinical signs. Latent herpesviruses such as EBV and CMV also persist in donors. BSL-2 practices mandate use of Class II biological safety cabinets with HEPA-filtered laminar flow for any aerosol-generating procedures, limited laboratory access, biohazard signage, mandatory personal protective equipment including gloves and lab coats, eye protection when splashing possible, availability of autoclave for waste decontamination, and use of effective disinfectants like 10% bleach. Personnel require bloodborne pathogen training and HBV vaccination. Liquid waste is chemically disinfected. Unlike BSL-1 reserved for non-pathogenic lab strains, BSL-2 addresses moderate risk. Fixed paraffin-embedded tissues are exempt after complete fixation. Fixation with formalin inactivates most pathogens rendering samples safer for histology processing outside biosafety cabinets. This knowledge strengthens laboratory safety, protocol reproducibility, and regulatory compliance critical for translational research and clinical applications, ensuring reliable data and workforce protection.

Ref: CDC NIH BMBL 6th Ed. Section IV Lab Biosafety Level Criteria, Human Cell Lines; https://www.cdc.gov/labs/BMBL.html - BSL-2 for human tissues.

View Details