Thanks to these following teams and company: O.REILLY, BIO-RAD and 2018 iGEM Team Worcester, we are able to create a gene gun of our own. But also, we have our own design and improvement over them.
We searched the Internet and found the article about the DIY gene gun. The author decided to use bicycle CO2 tire inflator to obtain high-pressure gas. However, we didn’t adopt his method. The reasons are as follows. First, the gas pressure in Co2 inflator can’t satisfy our needs. Average commercial CO2 inflator provide up to 130 psi gas pressure, which can’t even meet the minimum pressure requirement of gene gun. Moreover, the limited size of inflator makes frequent experiments inefficient. Our team contacted the Maker Workshop in campus, and the instructor permitted us to use the high-pressure air pump which meet our needs. The air pump solved both problems since it is reusable and powerful enough to make high pressure gas. The air pump integrated a pressure gauge, saved money buying a new gauge to the system.
We adopted the original structure of the gun muzzle. We designed a detachable pressing block at the muzzle, which can not only effectively fix the macrocarrier and bullet (and keep them a certain distance), but also facilitate the disassembly and replacement of the macrocarrier or bullet. We have designed a cone for the muzzle of the gun, which is convenient for the bullet to scatter evenly, thus optimizing the firing result. It is worth mentioning that because of the air pump and block pressing structure, we can accurately provide the required pressure and make the gun enter the launching state with efficiency and safety. Therefore, we remove the rupture disk in the original design, which can greatly save our experimental cost.