Memorandum
Date: June 16, 2012
To: English 3301 Class
From: Faraz Arastu
Subject: Glen-Pak DNA Purification Protocol
The modified protocol for the Glen-Pak 3g DNA Purification cartridge is designed to purify DNA synthesized in reverse on a 5umol scale. The previous method was too costly, low-yielding, and time-consuming, but the protocol published by Glen Research is validated only for 10-20umol scales of DNA made in the forward direction. The modified protocol combines the process from the previous method with the purification medium from Glen Research. This is similar in spirit to using different software to operate the same piece of hardware. Once again, this hybrid technique will optimize concerns with cost, yield, and efficiency of purifying 5umol scales of Reverse-DNA.
This procedure is meant to be used by the next co-op student who will take over my position at ChemDiscovery. Since the company generally recruits students with at least one previous biotechnology lab experience, the student will likely have a strong background in working with DNA. The protocol will be used in intervals, since DNA is made heavily in the first three weeks of the internship, followed by a long period of disuse before another heavy period of use. Initially, it is meant to guide the student through the purification process stepwise until he/she is comfortable enough not to rely on it. Later, it is meant to refresh the student’s memory for the second round of repeated purifications. This new protocol will be available to the co-op in a password-protected file server system at the company. As it is in PDF form, the document is locked for editing. However, the student will be able to print copies wirelessly.
In terms of design, I have chosen a lab format where materials and quantity are listed first, followed by the procedure, which is divided chronologically, i.e. prep work, purification, quality control. This ensures that the student will not start the procedure until all materials are accounted for. On another note, I have omitted certain details included in Glen Research’s procedure, while including others which better fit the needs of the co-op. I omitted Glen’s explanations of how to perform certain calculations which are a matter of simple algebra. I also modified the concentration of solvents in the wash steps based on data I have from previous DNA purifications. In addition, I have included vacuum and time settings for each step, as well as quality control checks which Glen did not specify. Overall, the core procedure is the same, since I am using the same solvents in the same order. The modifications fine-tune the concentrations and exposure times of these solvents as well as adding steps for quality assurance.
Under normal circumstances, I would present this protocol in a formal lab group meeting along with the data I used to validate it. After posing questions and criticism about the protocol, the group would decide whether my data was complete and whether to add this protocol into our standard operating procedures. If not, they would suggest further experiments to validate the method. In this case, I am assuming that I have already received approval for this protocol from my team and that I am responsible for passing it on to my replacement.
Attachment: Glen-Pak Purification of 5umol Scale Reverse-DNA