Question

I am going into the field soon to sample a very remote environment. For reasons that are unimportant here, I would like to extract bacterial DNA from these samples in the field.

I will have access to electricity, but no heavy equipment such as centrifuge. My goal is to extract DNA from these hypersaline liquids for long-read sequencing and subsequent metagenomic analysis with a focus on DNA methylation. My plan is to filter large volumes to have sufficient biomass onto a filter from which extraction will occur (think seawater type samples).
Any suggestions for an equipment-less DNA extraction kit?

Answer 1

A simplified DNA extraction method for bacterial DNA in remote environments can be accomplished with a buffer of water, dish detergent, and salt, followed by filtration, application of the buffer, DNA precipitation, and resuspension in TE buffer or water.

Step-by-step explanation:

To extract bacterial DNA in the field without the use of heavy equipment like a centrifuge, you can adopt a simplified protocol using basic materials. A common DNA extraction buffer that can be used consists of water, dish detergent, and table salt. The detergent helps lyse the cells by breaking down the lipids in the cell and nuclear membranes, while the salt helps to remove proteins from the DNA.

Field-Friendly DNA Extraction Protocol

1. Prepare the DNA extraction buffer by mixing 900 mL of water with 50 mL of dish detergent and two teaspoons of table salt. Mix by inversion.
2. Collect your hypersaline environmental samples and filter them onto a filter appropriate for trapping bacteria.
3. Apply the DNA extraction buffer to the filter to lyse the cells and release the DNA.
4. Wash the filter with the buffer to ensure all the DNA is collected.
5. Use ethanol or isopropanol to precipitate the DNA.
6. Visually identify the precipitated DNA and let it dry.
7. Resuspend the DNA in a small volume of TE buffer or water for storage.

While this protocol is a general guide, specificity to the sample type, such as hypersaline liquids, may require modifications to buffer components or concentrations.