An Economical Laminar-flow Microbe-free Chamber for Culturing Small Plants

An economical plant growth chamber, 16 cm in diameter and 50 cm high, was made from two 4-liter glass beakers. The bottom was removed from one beaker, and a 1 cm hole cut in the bottom of the other. The bottomless beaker, when placed atop the other, telescoped slightly for firm support. Sand was placed in the bottom of the chamber as a growth substrate. A polyethylene bag was placed over the two beakers and filtered air (under pressure) and nutrient solution entered the chamber through rubber tubing. Six chambers, each with an open petri dish of nutrient agar in the bottom, were tested for 2 weeks, and all dishes remained microbe-free. The laminar flow of air between the plastic bag and the glass walls of the beakers prevented microbes from entering the chamber. The chambers supported good growth of corn and soybean seedlings for 4 weeks when a sterile nutrient solution was added to the sand as needed