May 26, 2026
Preparation of demi-spinners
- Melissa Pitton1,
- Rachel E. McLeod1,
- Lea Caduff1,
- Ayazhan Dauletova1,
- Jolinda de Korne1,
- Charles Gan1,
- Camille Hablützel1,
- Aurélie Holschneider1,
- Seju Kang1,
- Guy Loustalot1,
- Patrick Schmidhalter1,
- Linda Schneider1,
- Anna Wettlauffer1,
- Daniela Yordanova1,
- Timothy R. Julian2,
- Christoph Ort1
- 1Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland;
- 2Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland, Swiss Tropical and Public Health Institute, Allschwil, Switzerland, University of Basel, Basel, Switzerland
Protocol Citation: Melissa Pitton, Rachel E. McLeod, Lea Caduff, Ayazhan Dauletova, Jolinda de Korne, Charles Gan, Camille Hablützel, Aurélie Holschneider, Seju Kang, Guy Loustalot, Patrick Schmidhalter, Linda Schneider, Anna Wettlauffer, Daniela Yordanova, Timothy R. Julian, Christoph Ort 2026. Preparation of demi-spinners. protocols.io https://dx.doi.org/10.17504/protocols.io.eq2lyo48egx9/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: March 19, 2026
Last Modified: May 26, 2026
Protocol Integer ID: 313595
Keywords: purification of total nucleic acid, purification, spinner, inhibitor removal steps of the protocol, inhibitor removal step, total nucleic acid, preparation, extraction, assembly
Abstract
This protocol describes the preparation and assembly of so-called demi-spinners, used for the purification of total nucleic acids and inhibitor removal steps of the protocol "Extraction and Purification of Total Nucleic Acids from Wastewater".
Materials
Consumables
- 14 mL culture tubes polystyrene (Huberlab: cat. no. 7.187 262)
- Pipette Tips GPS LTS 1000μL, nonfilter (Rainin: cat. no. 30389293)
- Pipette tips RC LTS 5000 uL, nonfilter (Rainin: cat. no. 17001133)
- Promega PureYield™ Minicolumns (included in Promega Wizard® Enviro TNA Kit, Promega cat. no. A2991)
Equipment
- Cutter or strong scissors
- 15 mL falcon tube rack to hold finished demi-spinners
- Small boxes (e.g. empty pipet tip boxes) to store reusable culture tube caps
Safety warnings
No direct safety measurements apply. Special care should be applied when cutting pipette tips apart, as the cut-off plastic part could be flung away when cut. The cut edges can be sharp, be careful when assembling the parts into a demi-spinner.
Scope
This protocol does not cover any analytical steps. The goal is the production of demi-spinners, which are a consumable used for the wastewater extraction process. Per sample, one demi spinner is needed.
Procedure
The procedure to assemble the demi-spinners includes several steps of cutting pieces followed by assembling the different parts into the final product. Schematic pictures show where to cut and what to assemble.
Cut a hole into the cap of the culture tube so it looks like a tunnel (Figure 1).
Figure 1: Cutting a hole into the culture tube caps
Cut the 5 mL pipette tip to create a funnel. Cut the pipette tip at both ends as indicated in Figure 2. At the slim end cut along the small indent where the pipette tip broadens. At the broader end cut 0.5 cm below the grooves. It does not have to be exact. However, too long tips may result in problems when closing the centrifuge and too short tips may end up in the funnel not properly reaching into the column, destabilizing the inside of the demi-spinner.
Figure 2: Cutting the 5 mL tips into the needed shape
Cut the 1 mL pipette tip to create a strut. Cut as indicated in Figure 3. Cut slightly above the line that can be seen on the pipette tip at the slimmer end of the tip. On the other end, cut right along the end of the grooves.
Figure 3: Cutting the 1 mL tips into the needed shape.
Remove the cap of the Promega PureYield Minicolumn. This can be done by cutting as indicated in Figure 4 or by cutting off the hinge while the cap is still closed. Remove the cap and toss it.
Figure 4: Removing the cap of the Promega PureYield Minicolumn
Assemble the demi-spinner in the order shown in Figure 5 so that it results in the final version as depicted in C.
Figure 5: Assembly of the demi-spinners
Protocol references
Pitton, M., McLeod, R.E., Caduff, L. et al. A six-plex digital PCR assay for monitoring respiratory viruses in wastewater. Nat Water 3, 1174–1186 (2025). https://doi.org/10.1038/s44221-025-00503-x.
Acknowledgements
The work published is based on Pitton et al. (2024) DOI: 10.1038/s44221-025-00503-x
This study was funded by the Swiss National Science Foundation (SNSF Sinergia grant number CRSII5_205933)
and by the Swiss Federal Office of Public Health (grant numbers 142006108/334.0-101/26 and 142006655/334.0-107/12) granted to C.O. and T.R.J.
Protocol Prepared for Protocols.io by: Darine D'Adam, Eawag, Swiss Federal Institute of Aquatic Science and Technology