Skip to content
日本語Newsletter

How much did purification lose?

Step recovery and overall process yield calculator

From the amount before and after a step, gives the share that step kept (step recovery), and the share of the starting amount left after several steps (overall yield).

When to use itUse it to find where a purification train loses the most product, or to estimate how much product the whole process will deliver.

Prefilled with an example: a step that takes in 1,000 mg and gives 850 mg, followed by four steps at 90% recovery each. Change any value and the result updates.

mg

The amount before the step, worked out as titer × volume or similar.

mg

The amount after the step, in the same unit as the amount in.

%

The four fields from here are for overall yield. Enter 100 for no loss.

%

The share kept by step 2.

%

The share kept by step 3.

%

Enter 100 if there are only three steps.

Share kept by this step (step recovery)85 %
Share left after four steps (overall yield)65.61 %
Amount lost in this step150 mg

This step kept 85% of what went in and lost 150 mg. After all four steps, 65.61% of the starting amount remains. Working on the step with the lowest recovery first does the most for overall yield.

How to read it (acceptance levels differ by step)

  • How overall yield worksEvery step multiplies the lossThe more steps, the more the total shrinks, even when each step recovers well (four steps at 90% leave about 66%). Improving the weakest step pays off most.
  • Recovery lower than expectedTrack down where it wentLosses take different routes in different steps: adsorption to resin or containers, precipitation, passage through membranes, wash fractions. Following the mass balance of what went in and what came out narrows down the cause.
  • Recovery versus purityDo not decide on yield aloneWidening the pooling window raises yield but also brings in more impurities. Settle on yield together with purity and productivity.

How it is calculated

The first two fields give the recovery of one step, and the last four give the overall yield. Overall yield is the product of the step recoveries.

step recovery (%) = amount after ÷ amount before × 100 overall yield (%) = r1 × r2 × r3 × r4 ÷ 100³

Source: Step recovery is the amount after the step ÷ the amount before it, and overall yield is the product of the step recoveries. This is basic mass balance.

With your numbers

  1. step recovery = after ÷ before × 100 = 850 ÷ 1,000 × 100 = 85 %
  2. overall yield = r1 × r2 × r3 × r4 ÷ 100³ = 90 × 90 × 90 × 90 ÷ 10⁶ = 65.61 %

Limits of this calculation

  • Acceptable recovery differs widely by step, resin and product. There is no single standard.
  • Overall yield is a simple product of the step recoveries. Consider losses carried between steps and measurement error separately.
  • Values shift with the assay used to measure the amount (titer, A280, activity and so on). Compare only results from the same method. Treat the result as an estimate for learning.

Primary sources

Every calculator gives an estimate for learning, built on published information and primary sources. Real decisions follow the applicable guidance and expert judgment.