Feb 25, 2026
Cell pellet harvesting methods for Karlodinium veneficum PLY720, Kryptoperidinium triquetrum CCAP 1116/3 and Nitzschia laevis UTEX_B_2047
- 1Department of Biochemistry, University of Cambridge
Protocol Citation: Will Lewis, Ross F. Waller 2026. Cell pellet harvesting methods for Karlodinium veneficum PLY720, Kryptoperidinium triquetrum CCAP 1116/3 and Nitzschia laevis UTEX_B_2047. protocols.io https://dx.doi.org/10.17504/protocols.io.n2bvj1qrwvk5/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: February 03, 2026
Last Modified: February 25, 2026
Protocol Integer ID: 242539
Keywords: cell harvesting, methodology for cell harvesting, cell pellet harvesting methods for karlodinium veneficum ply720, cell pellet harvesting for karlodinium veneficum ply720, cell pellet harvesting method, cell pellet harvesting, karlodinium veneficum ply720, kryptoperidinium triquetrum ccap, nitzschia laevis utex-b-2047 culture
Funders Acknowledgements:
Gordon and Betty Moore Foundation
Grant ID: GBMF9194
Disclaimer
DISCLAIMER – FOR INFORMATIONAL PURPOSES ONLY; USE AT YOUR OWN RISK
The protocol content here is for informational purposes only and does not constitute legal, medical, clinical, or safety advice, or otherwise; content added to protocols.io is not peer reviewed and may not have undergone a formal approval of any kind. Information presented in this protocol should not substitute for independent professional judgment, advice, diagnosis, or treatment. Any action you take or refrain from taking using or relying upon the information presented here is strictly at your own risk. You agree that neither the Company nor any of the authors, contributors, administrators, or anyone else associated with protocols.io, can be held responsible for your use of the information contained in or linked to this protocol or any of our Sites/Apps and Services.
Abstract
A methodology for cell pellet harvesting for Karlodinium veneficum PLY720, Kryptoperidinium triquetrum CCAP 1116/3 and Nitzschia laevis UTEX_B_2047 cultures.
Materials
Liquid N2 dewar
1000 µl pipette with sterile filter tips
50 ml centrifuge tubes
Sterile 2 ml tubes
Tube racks
Centrifuge with adapter for 50 ml tubes
Centrifuge with adapter for 2 ml tubes
1 litre lab bottles for collecting decanted waste supernatant to be decontaminated/biologically inactivated.
Safety warnings
Ensure you have been trained and are permitted by your department to handle liquid nitrogen in a safe manner, and always use necessary PPE.
Before start
Cool centrifuges to 4°C.
Cell harvesting
20m
Grow algal cultures in 200 mL volumes in a T175 tissue culture flask.
Cool centrifuges for 50 mL and 2 mL tubes to 4°C.
For each culture being harvested, label four 50 mL tubes with the sample and replicate ID, and a 2 mL tube with the sample and replicate ID and the current date. I typically label both the lid and the side of the 2 mL tubes with this information to ensure the tubes are still identifiable if one of the labels is accidentally destroyed during storage or processing.
For Nitzschia leavis, the cells adhere to the bottom of the flask, and therefore must be removed by scraping the flask surface using a 32 cm cell scraper.
For each replicate culture, gently invert the culture flask several times to homogenise the culture and then transfer four 50 ml aliquots of the culture to four 50ml centrifuge tubes labelled with the corresponding identifier for that sample and replicate.
Centrifuge the 50 ml tubes at 4000 x g for 5 minutes at 4°C.
Decant and dispose of the supernatants from each tube by gentle pouring, leaving the pellet in the bottom of the tubes. Inverting the tube in one smooth hand motion to remove the supernatant. This should remove the majority of the liquid but will leave a small volume of liquid on the walls of the tubes. This is desirable as once the tube is reinverted, the remaining liquid will run back down to the pellet. This small volume of remaining liquid, which typically is <1000 µl in volume, can then be used to resuspend the pellet using a p1000 pipette.
Once resuspended, pool the pellets for tubes originating by combining them using a 1000 µl pipette and transfering them to the 2 ml microcentrifuge tube with the corresponding identifier for that sample and replicate.
Centrifuge the microcentrifuge tube at 5000 x g for 5 minutes at 4°C and then dispose of the supernatant using a 1000 µl pipette.
Flash-freeze the cell pellets by resealing the 2 mL tubes and dropping them into a liquid N2 bath for several minutes. Long metal tweezers can be used to hold the tube beneath the surface of the liquid nitrogen and ensure proper contact and freezing. The tubes can then be removed and stored at -80 °C until further processing for RNA or protein extraction.