Category: Lab Notes
Protocol – Feeding Suspension Culture (Complete Replacement of Medium)
Complete replacement of culture medium from suspension culture involves cell harvesting by centrifugation and resuspension of the cell pellet in fresh growth medium. This method is ideally the best way to feed suspension culture and is often used when a. you observe dead or sick cells/suspended particles in culture; b. medium color (phenol red-containing medium) has turned yellow very quickly; c. you can not afford cell loss. Complete replacement of culture medium is ideally the best way to feed suspension culture. Since this procedure takes time and involves an additional centrifugation step to harvest cells, often researchers partially replace the medium that takes just a few minutes. However, partial medium replacement is associated with the loss of cells from the culture.
Protocol – Feeding Suspension Culture (Partial Replacement of Medium)
Replacement of culture medium from suspension culture is a bit tricky job as cells float in the medium. Ideally, cells are harvested from the medium by centrifugation and then resuspended in a fresh culture medium. However, in practice, a part of the culture medium is replaced with a fresh culture medium without harvesting the cells. This procedure is associated with the loss of cells.
Protocol – Thawing and Revival of Cryopreserved Cells
This protocol describes the revival process of cryopreserved adherent cells. The revival process involves rapid thawing of cryopreserved cells followed by removal of freezing medium which contains cryoprotectant, in this case, DMSO. The freezing medium can be removed immediately just after thawing the cells by centrifugation. Alternatively, cells are allowed to adhere to the culture dish followed by washing and addition of fresh growth medium.
Comparison of TAE and TBE Electrophoresis Buffers
Both TAE (Tris-Acetate EDTA) and TBE (Tris-Borate EDTA) are common electrophoresis buffers for DNA agarose gel electrophoresis. However, they are quite different in nature, have some useful features and also some disadvantages. You can maximize your results by choosing an electrophoresis buffer depending on your application. The following table lists their properties, and advantages and disadvantages, and also provides explanation for their peculiar behaviour.