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All plasmids, bacteria, DNA solutions, and vectors are to be treated as biohazar

ID: 51232 • Letter: A

Question

All plasmids, bacteria, DNA solutions, and vectors are to be treated as biohazard waste.
Describe the biohazard handling steps that should be followed for the following scenarios (Your steps should be based on the basic NIH safety guidelines for lab operations with recombinant DNA. (Hint: See Lab Manual Introduction) (15 points):


The culture you were about to use for your miniprep spills on your skin


Your bacterial culture spills on the countertop


The glass tube holding the liquid culture drops to the floor and shatters


You need to dispose of your purified plasmid because it was not pure enough for your downstream applications.

Explanation / Answer

Answer:

There are generally four routes to exposure to hazardous chemicals that you should keep in mind while handling them:         

Inhalation                             – avoid by the use of fume hoods and masks

Skin & eye contact              – avoid by the use of lab coats, gloves, and goggles

Ingestion                               – avoid eating or drinking in the lab or leaving the lab without removing gloves

and washing hands

Injection                                                – dispose of broken glass and needles properly

Because chemicals pose so many different kinds of hazards, there are no simple rules of thumb for safe handling of them all except for some common sense measures:

Here are some specific tips for handling the different types of hazardous chemicals:

Biological Safety: Containment

You will be working with live organisms in many biotechnology labs, so it is important to be able to assess any biological hazards that they may pose and to treat them accordingly. In general, a live organism is considered a biological hazard if its release into the environment could have an effect on the health of the environment in general or humans in particular. This includes known pathogens to humans, plants, or animals, as well as benign organisms containing recombinant DNA that could render the recombinant host dangerous. In fact, the recombinant DNA itself should be treated as a biosafety hazard, since it is usually inserted into a vector that could transform organisms in the environment if released. Similarly, tissue cultures of human or animal cells should be treated as a biohazard: while they would not survive if released into the environment, they contain recombinant DNA.

The routes of exposure to infectious agents are the same as those of hazardous chemicals: inhalation, contact with eyes and skin, ingestion, and injection. The same general precautions should be taken in handling biological hazards as the guidelines above for handling chemical hazards, especially toxic ones. Here are some general practices to maximize biological safety:

Seventy percent of recorded laboratory-acquired infections are due to inhalation of infectious particles, so special precautions should be taken to avoid producing aerosols when working with pathogens. While performing activities that mechanically disturb a liquid or powder, the biotechnologist should make the following adjustments.

                Activity                                                                                                  Adjustment