More Preparation Procedures

Laminar Flow System

Before using the biology microscope, prevention of airborne contamination while manipulating cultures must be observed. The transfer area is ventilated by continuous piston-like displacement of air that has been passed through a high efficiency particulate air or HEPA filter. These filters are 99.97% efficient in removal of particles 0.3um in diameter and for practical purposes they sterilize the ambient air of the transfer room.

Purification and Standardization of Water for Tissue Culture

Most hospitals or research laboratories are equipped with a central water purification system aside from the biology microscope and other culture devices. If there is some doubt about contamination of purified water, it is advisable to retreat the water at the end point.

Demineralization of Water

The process of demineralizing water by ion exchange involves the conversion of salts to their corresponding acids by hydrogen cation exchange and consequent removal of these acids by anion exchange.

Distillation involves the evaporation of water from a solution and recovering the desired constituent by condensation. It is an efficient method of purifying water, which does not use a biology microscope. For the average tissue culture laboratory, an efficient system for obtaining high purity water would be a mixed bed ion exchanger followed by a glass still. Plastic carboys are the most common water storage vessels in tissue culture laboratories. But oftentimes, questions of contamination arise. The most practical storage vessel is a borosilicate glass carboy tightly sealed. Conductivity is the easiest and most frequently used method of determining water purity.