Fast and Efficient Ethanol Evaporation in DNA Extraction: Development of a Portable Mini Air Flow Cabinet

Abstract

Polymerase Chain Reaction (PCR) is an important technique in molecular biological studies, but residual ethanol in DNA samples can interfere with its efficiency and yield. As a result of the inhibitory effect of ethanol on Taq polymerase, secondary structures can form in the DNA template that interferes with primer binding and extension. To address this issue, this portable mini air flow cabinet (15 cm×8 cm×15 cm) was developed to dry the remaining ethanol traces rapidly. Cost of production for this tool was around 500 LKR. Under room temperature, it takes 30 to 45 minutes to evaporate the remaining (15-20 μl) ethanol in the final extraction. Scientists utilize methods such as vacuum-drying and oven-drying to speed the drying process. This apparatus uses an electrically operated fan (12 V/4500 rpm) to generate an airflow that dries the remaining ethanol from the DNA pellets. This tool takes 2.27 (±0.03) minutes to evaporate 1μl ethanol and without this tool it takes 5.32 (±0.03) minutes to evaporate the same amount of ethanol in an open room (25◦C, 79% Relative humidity). Overall use of this tool has significantly reduced (P < 0.05) the ethanol evaporating time compared to without tool ethanol evaporating in an open room. (25◦C, 79% Relative humidity). The tube holding base plate is built to give a slight tilt to the tubes at the horizontal axis, ensuring that the ethanol moves downward along the tube wall, leading to a thin spread and faster drying. The mini airflow cabinet has the capacity to dry 12 microcentrifuge tubes of 1.5 ml in a single run. This innovative tool requires little maintenance and very easy to use, making it a perfect choice for laboratories and research facilities of all sizes due to its simplicity and ease of use.