If you had to prove that your method for cleaning chromatography columns works and you had different sizes and shapes of columns, which one would you pick as a worst case to focus on? You have tall, skinny columns and short, fat columns, as well as different sizes. These are cylindrical glass columns that range from a diameter of 1.6 cm to 5 cm and a length of 10 cm to 100 cm. Assume they all contain the same chromatography media and are all rinsed with the same linear flow rate. Assume that they all have the same basic design and are composed of the same materials. These would be cleaned by running a small volume of sodium hydroxide throught the column (same percent of total column volume for each column) and then rinsed with a salt solution (buffer). Important considerations are that the sodium hydroxide contacts all portions of the media for a minimum length of time and rinsing sufficiently removes all of the sodium hydroxide. I ask because I'm not sure of what sort of fluid dynamics are going on within the column and whether column shape or size might affect how well the solutions are able to reach all areas of the column.