Chromatography run planner
Start with your feed, enter the capacity of each medium, and see how long the batch takes on a packed column and on a MonoCore™ capsule — cycles included. Nothing is sent anywhere; the calculation runs in your browser.
That is 2 g of product to capture. How many cycles each format needs depends on its binding capacity — enter that below.
From the datasheet of your medium, at the residence time you load at.
Residence time 4 min · 1.25 mL/min. Protein A resins are loaded at roughly 1–6 minutes.
5 mL/min. Washes and elution are normally run faster than the load.
MV = monolith volume, the monolith equivalent of a column volume.
Stated on the MonoCore™ datasheet together with the conditions it applies to — see the datasheet for the chemistry you are using.
Residence time 6 s · 18 mL/min, within the recommended range of 5–10. Note that the capacity figure on the datasheet is measured at 4 MV/min — the capacity that applies at your load flow rate is the one to enter above.
18 mL/min. Recommended range 5–10 MV/min.
| Step | Volume or time | Your column | MonoCore™ | ||
|---|---|---|---|---|---|
| 5 min | 30 s | ||||
| 1,000 / 1,000 mLfrom feed & capacity | 13 h 20 min | 55.6 min | |||
| 5 min | 30 s | ||||
| 3 min | 18 s | ||||
| 3 min | 18 s | ||||
| 3 min | 18 s | ||||
| 3 min | 18 s | ||||
| 10 min | 1 min | ||||
| One cycle | 13 h 52 min | 58.8 min |
Enter a binding capacity for both beds to see the time for the whole batch. Without it, only the length of a single cycle can be calculated — and a cycle time on its own says nothing about whether a bed is large enough for your batch. Both figures are on the datasheet of the medium, next to the conditions they were measured under.
Caustic cleaning is run once the batch is through, not after every cycle — so it is counted once, not per cycle.
What this is and is not. The planner gives a good idea of the time a method takes and where the difference between two formats comes from. It is not a simulation of your process: valve switching, pump ramp-up and settling, fraction collection, UV-triggered decisions, system equilibration, buffer preparation, sample handling and analytics are all outside it, and on a short cycle they are not negligible. Treat the numbers as an order of magnitude for planning, not as a specification.
It also does not check pressure limits, resolution or buffer compatibility, and the capacity figures are only as good as what you enter — a datasheet capacity applies at the residence time, bed height and feed it was measured with. See how to read a dynamic binding capacity figure.
How the cycle time is calculated
Every step takes its volume divided by the volumetric flow rate. The planner keeps flow rates in bed volumes per minute, because that is the unit that transfers between formats:
For a step entered in millilitres — the load, usually — the bed volume comes back into it, because a fixed volume of feed takes longer on a small bed than on a large one at the same number of column volumes per minute:
A step entered in minutes is simply that many minutes on both sides. This matters more than it looks: caustic cleaning is driven by contact time, not by how many bed volumes pass through, so a CIP step counted as a volume would let a small bed appear to clean in seconds. The same applies to holds and sanitisation.
The cycle time is the sum over all steps. Reordering steps does not change it — the order is there so the method reads like the method you actually run, and so a step you add lands in the right place.
CV and MV — the same idea on different beds
A column volume (CV) is the volume of the packed bed. A monolith volume (MV) is the volume of the monolith. Both express buffer volumes and flow rates independently of scale, which is why a method written in column volumes transfers to a capsule as the same number of monolith volumes. On MonoCore™ capsules one MV is 1.8 mL or 5.4 mL.
The difference between the two sides of the planner is therefore not the method but the flow rate per bed volume. A packed bed is typically run at a residence time of a few minutes — a fraction of a column volume per minute. A convective medium does not rely on diffusion into bead pores, so it is run at several bed volumes per minute; the recommended range for MonoCore™ capsules is 5 to 10 MV/min. If you have a linear velocity in cm/h rather than a flow rate, convert it with the residence time calculator.
What the planner deliberately does not do
- It is only as good as the capacity figures you enter. The number of cycles — and therefore the whole comparison — follows from them. A datasheet capacity applies at the residence time, bed height and feed it was measured with, so it does not transfer unchanged to your process. What that means is set out in how to read a dynamic binding capacity figure.
- It is not a simulation of your system. Valve switching, pump ramp-up and settling, fraction collection, UV-triggered decisions and system equilibration are outside it, and on a short cycle they are not negligible. The result is a good order of magnitude for planning, not a specification.
- It does not check pressure. Whether a flow rate is within the limit of your column, capsule, tubing and system is a question for the datasheets, not for a calculator.
- It does not predict resolution. Cycle time and separation quality are independent; a faster run is not a better separation.
- It does not include everything that takes time. Buffer preparation, system equilibration, sanitisation between products, sample handling and analytics are often a larger share of the working day than the chromatography itself.
When cycle time is worth optimising
Rarely, and then decisively. If a capture step runs once a week and nothing waits for it, the format is not your problem. It becomes a real constraint in three situations: when a batch is larger than the bed and has to be captured over several cycles, when process development is screening conditions and each experiment costs a day, and when a facility is the bottleneck rather than the molecule.
There is a fourth case that is not about throughput at all. For an acid-sensitive product, a shorter elution means less time at low pH, which is a product quality argument rather than a scheduling one — though only part of the exposure, since the eluate stays acidic until it is neutralised. The full picture is in how to elute from Protein A without acid.
Frequently asked questions
How do you calculate the cycle time of a chromatography run?
Add up the time of every step, then multiply by the number of cycles the batch needs. A step takes its volume divided by the volumetric flow rate: 5 column volumes on a 5 mL column at 5 mL/min takes 25 mL ÷ 5 mL/min = 5 minutes. Two details decide whether the total is realistic. The load usually runs at a slower flow rate than the washes and elution, so the two are entered separately. And caustic cleaning is not part of a cycle at all — it is run once the batch is through, so it is counted once rather than charged to every cycle.
What is the difference between CV and MV?
They are the same idea on different beds. A column volume (CV) is the volume of the packed bed; a monolith volume (MV) is the volume of the monolith. Both are used to express buffer volumes and flow rates independently of scale, so a method written in CV transfers to a capsule as the same number of MV. On MonoCore™ capsules one MV is 1.8 mL or 5.4 mL depending on the format.
Why does the same method take a different time on a monolith?
Because the flow rate per bed volume differs, not because the method changes. A packed bed is usually run at a residence time of a few minutes, which is a fraction of a column volume per minute. A convective medium does not depend on diffusion into beads, so it can be run at several bed volumes per minute — the recommended range for MonoCore™ capsules is 5 to 10 MV/min. The same sequence of steps therefore finishes sooner. Resolution, capacity and pressure limits are separate questions the planner does not answer.
Does a shorter cycle mean a better process?
Only where cycle time is the constraint. If your column runs once a week and nobody waits for it, a faster format changes little. It matters when the step is repeated — multi-cycle capture of a large batch, process development screening, or a clinical campaign where the suite is the bottleneck. It also matters for acid-sensitive products, because a shorter elution means less time at low pH.
Is the load time included?
Yes, and it is usually the longest step. The load volume is not entered directly: it follows from the titre, the batch volume and the binding capacity of each medium, so each bed loads what it can actually hold. That is why the load line shows two different volumes, and why the comparison is made over the whole batch rather than over one arbitrary cycle.
Are the default settings a fair comparison?
They are chosen so they are not flattering to us, and you should still replace them with your own. The column is loaded at a 4-minute residence time and runs its other steps faster, the way a platform method does — timing every step at the load flow rate would inflate the difference considerably. The capsule loads and runs at 10 MV/min, the top of the recommended range — worth knowing, because the capacity figure on the datasheet is measured at 4 MV/min, so the capacity you enter should be the one that applies at the rate you load at. Caustic cleaning is counted once after the last cycle rather than per cycle, because that is how it is actually run; charging it to every cycle would penalise whichever format needs more of them. And if your current medium is a membrane adsorber rather than a packed bed, it already runs at bed volumes per minute and most of the difference disappears.
Does the planner check whether my method is valid?
Only partly. It times a method and, if you enter a titre and a capacity figure, it checks whether the load fits and tells you how many cycles the batch needs. It does not check pressure limits, resolution or buffer compatibility. The capacity check is also only as good as the figures you enter: a datasheet capacity applies at the residence time, bed height and feed it was measured with. Comparing cycle times between two beds of different volume compares time, not capability.