What's the DEPC water protocol for removing contamination from racks and other utensils in lab?
Honestly, I've never heard of this. DEPC-treated water is not for cleaning.
DEPC is the substance used to purify the (already bidistilled) water itself, because DEPC inhibits nucleases; in the final step of preparing DEPC-treated water you autoclave it, and DEPC degrades, producing CO2 and H2O (I'm not sure exactly about its degradation products, but they shouldn't be chemically active). So, DEPC-treated water is simply very pure water without DNases and RNases, but it can't remove contaminations from any surface by itself. For this, you will need detergents, solvents, UV radiation, autoclaving and other cleansing methods depending on contamination type and utensils type.
For example, for cleaning lab surfaces from bacteria and grease we use 70% ethanol solution; for removing DNA traces ethanol is uneffective and you need either UV or chlorine-based cleaner (like diluted Bleach). We usually wash lab glassware manually with detergent, then rinse it with dH2O, seal with aluminium foil and autoclave.
However, nucleases are of the most persistent contaminants, they sometimes don't degrade even after autoclaving, so if you work with RNA you should use single-use plasticware labeled "RNAse free" and RNAse-free water as a solvent (you either buy this water or prepare it yourself using DEPC); you also may use specific products like RNaseZAP to clean lab surfaces. Make sure you work in a clean room, wear fresh gloves and don't exhale air in your sample, and so on.
To make DEPC-treated water, you should add MQ-filtered (bidistilled) water to the autoclaved vessel, add 1:1000 volume of DEPC, close the vessel and let it stay on the table for an hour or more. After this, you autoclave this water for 20-40 minutes (don't forget to loosen the lid so it wouldn't explode from the pressure)!
Honestly, I've never heard of this. DEPC-treated water is not for cleaning.
DEPC is the substance used to purify the (already bidistilled) water itself, because DEPC inhibits nucleases; in the final step of preparing DEPC-treated water you autoclave it, and DEPC degrades, producing CO2 and H2O (I'm not sure exactly about its degradation products, but they shouldn't be chemically active). So, DEPC-treated water is simply very pure water without DNases and RNases, but it can't remove contaminations from any surface by itself. For this, you will need detergents, solvents, UV radiation, autoclaving and other cleansing methods depending on contamination type and utensils type.
For example, for cleaning lab surfaces from bacteria and grease we use 70% ethanol solution; for removing DNA traces ethanol is uneffective and you need either UV or chlorine-based cleaner (like diluted Bleach). We usually wash lab glassware manually with detergent, then rinse it with dH2O, seal with aluminium foil and autoclave.
However, nucleases are of the most persistent contaminants, they sometimes don't degrade even after autoclaving, so if you work with RNA you should use single-use plasticware labeled "RNAse free" and RNAse-free water as a solvent (you either buy this water or prepare it yourself using DEPC); you also may use specific products like RNaseZAP to clean lab surfaces. Make sure you work in a clean room, wear fresh gloves and don't exhale air in your sample, and so on.
To make DEPC-treated water, you should add MQ-filtered (bidistilled) water to the autoclaved vessel, add 1:1000 volume of DEPC, close the vessel and let it stay on the table for an hour or more. After this, you autoclave this water for 20-40 minutes (don't forget to loosen the lid so it wouldn't explode from the pressure)!
DEPC is volatile and toxic, So you cannot use it to inhibit RNase on the experiment table. For that, I agree with @ Ali Mahmoudpour to use 70% ethanol to wipe the table.
0.1% DEPC can be only used for RNase-free plastic products treatment, such as EP tube, pipette tips, and so on. you can put 0.1% DEPC and plastic to be treated into a sealed plastic bag. 37oC 24hr incubation is necessary. Additionally, DEPC is unstable under the light, so you should keep the bag in dark place during the incubation. After the incubation, you should pour-out the DEPC water into a triangular flask, and reseal the bag. At last, autoclave the DEPC water and treated plastic at 121 oC for at least 20 minutes, and DEPC will resolve to H2O and CO2. Then you can use the RNase-free DEPC water and plastic. All the experiment except the autoclave I mentioned above must be operated in fume cupboard.
The Metal and glass products can be treated at 180 oC for 5 hr to make the RNase inactivation.
Yes I had never use DEPC is a buffer for RNA !!! use autoclave to sterilization!!!
you can Add 1000 ml of mili q water or double distilled water plus 1 ml of DEPEC Soak your utensils good in these water , make incubation about 15 hrs till the DEPEC go out.
DEPC is not advisible for cleaning lab utensils, you can clean your lab utensils with detergent and then rinse with distilled water and go for autoclaving @121C for 20 mins.
- Badges
- Science topic
- Similar topics
- Biological Science
- Biochemistry
- Enzymology