TAE buffer, or Tris-acetate-EDTA, is a common solution in molecular biology laboratories. It functions as an electrophoresis running buffer and is essential for preparing agarose gels. Researchers use TAE buffer to separate nucleic acids, like DNA and RNA, during gel electrophoresis. This process involves applying an electric current to move charged molecules through a gel matrix. Understanding its components and properties is important for safe handling.
What Makes TAE Buffer a Concern?
TAE buffer contains three main ingredients: Tris base, acetic acid, and EDTA. In a typical 1x working solution, concentrations are approximately 40 mM Tris, 20 mM acetic acid, and 1 mM EDTA. While these individual chemicals pose hazards in concentrated forms, their diluted concentrations in TAE buffer generally present a lower risk. Safety Data Sheets (SDS) offer detailed hazard information for each component.
Tris (Tris(hydroxymethyl)aminomethane) can cause skin and serious eye irritation. It may also lead to respiratory irritation if inhaled. However, the diluted form in TAE buffer reduces these irritating effects compared to pure Tris.
Acetic acid, which gives vinegar its characteristic odor, is corrosive in concentrated forms. For example, glacial acetic acid can cause severe skin burns and eye damage. The 20 mM concentration in 1x TAE buffer is very dilute, significantly mitigating its corrosive properties. Common household vinegar, for context, contains 4-18% acetic acid.
EDTA (Ethylenediaminetetraacetic acid) is a chelating agent that binds to metal ions. In its pure form, this odorless, white crystalline powder can cause serious eye irritation and may be harmful if inhaled or if it contacts skin. The very low 1 mM concentration in 1x TAE buffer considerably lowers its potential for harm compared to the pure chemical.
Working Safely with TAE Buffer
Working with TAE buffer requires adherence to laboratory safety practices to minimize potential exposure. Personal protective equipment (PPE) creates a barrier between the user and the chemical.
Wear appropriate gloves, such as those made from nitrile rubber, to prevent skin contact. Eye protection, including safety goggles with side protection or a full face shield, should be worn to guard against splashes. Additionally, protective clothing helps prevent the solution from contacting skin and personal garments.
Adequate ventilation in the work area is important to prevent the accumulation of any airborne mists or vapors. Laboratories should have fume hoods or other local exhaust ventilation systems to ensure proper air exchange.
General laboratory safety rules also apply when handling TAE buffer. Avoid eating, drinking, or smoking in areas where chemicals are used to prevent accidental ingestion. Wash hands thoroughly after handling the buffer. Proper disposal of TAE buffer is also necessary, typically involving approved waste disposal methods rather than pouring it down drains.
What to Do in Case of Exposure
Despite preventative measures, accidental exposure to TAE buffer can occur, necessitating immediate first aid. Seeking medical advice promptly is important if symptoms develop or persist after any exposure. It is helpful to provide medical personnel with the Safety Data Sheet (SDS) for the chemicals involved.
For skin contact, immediately rinse the affected area with plenty of water for at least 15 minutes. Contaminated clothing should be removed. Washing the area with soap and water can further help remove the substance.
In case of eye contact, immediately flush the eyes with plenty of water for at least 15 minutes, ensuring eyelids are held open. Remove contact lenses if they are present and easy to remove. If eye irritation persists, seek medical attention.
If TAE buffer is inhaled, move the person to fresh air and keep them comfortable for breathing. For ingestion, rinse the mouth with water and do not induce vomiting. Prompt medical attention is necessary in cases of ingestion. Laboratories should have emergency eyewash stations and safety showers readily accessible in areas where chemicals are used.