How this calculation works
A serial dilution transfers only an aliquot from each source tube into the next tube. The unused source liquid stays behind; adding it to the receiving volume would describe a different procedure and produce the wrong concentration ledger. This page follows successive transfers into new tubes and reports the concentration, receiving volume and source remainder at every step. It differs from a single final-volume dilution calculation.
C_new = C_source × aliquot/(aliquot+diluent); source remainder = available−aliquotA worked example
Starting from concentration one hundred and a ten-millilitre source, transferring one millilitre into nine millilitres of diluent produces concentration ten in a new ten-millilitre tube. Nine millilitres remain in the original source. Repeating that transfer from the new tube gives concentration one and a total dilution factor of one hundred. Both transfers are possible because each source has enough volume when sampled.
Good to know
The arithmetic assumes complete mixing, conserved analyte and additive volumes. Adsorption, reaction, evaporation, growth and losses during transfer can change a real preparation and are excluded. No pipetting uncertainty or laboratory operating instruction is inferred from the numbers. The ledger helps inspect a stated series; suitable handling and measurement procedures remain specific to the material and equipment.
Reference: OpenStax — molarity and dilution (opens in a new tab) ↗
What this calculation answers
A serial dilution transfers only an aliquot from each source tube into the next tube. The unused source liquid stays behind; adding it to the receiving volume would describe a different procedure and produce the wrong concentration ledger.
This page follows successive transfers into new tubes and reports the concentration, receiving volume and source remainder at every step. It differs from a single final-volume dilution calculation.
The Dilution calculator solves one dilution relationship. This ledger also follows successive new receiving tubes and the unused liquid remaining in each source.
Use the right input conventions
Use one conserved-analyte concentration unit throughout, such as milligrams per litre. All aliquot and diluent volumes use millilitres, and each row starts a fresh receiving tube containing analyte-free diluent.
The first available source volume is entered separately. Later available volumes are the previous receiving-tube totals. A requested aliquot larger than its source is rejected instead of allowing a negative remainder.
Interpret the result
The concentration ratio multiplies across steps, while the final receiving volume depends only on the last aliquot and diluent. Two preparations can share a total dilution factor but leave different amounts available for later work.
Source remainders are displayed for inventory understanding. They are not merged into a combined stock, and the calculator does not assume they have the same concentration as liquid in later tubes.
Work through the example
Starting from concentration one hundred and a ten-millilitre source, transferring one millilitre into nine millilitres of diluent produces concentration ten in a new ten-millilitre tube. Nine millilitres remain in the original source.
Repeating that transfer from the new tube gives concentration one and a total dilution factor of one hundred. Both transfers are possible because each source has enough volume when sampled.
Where the model stops
The arithmetic assumes complete mixing, conserved analyte and additive volumes. Adsorption, reaction, evaporation, growth and losses during transfer can change a real preparation and are excluded.
No pipetting uncertainty or laboratory operating instruction is inferred from the numbers. The ledger helps inspect a stated series; suitable handling and measurement procedures remain specific to the material and equipment.
A few questions, answered
Why is source remainder not included in the next tube?
Each row describes an aliquot transferred into a new tube. Untransferred source liquid stays in its old tube.
What changes in the comparison?
Make the second transfer two millilitres; the final factor becomes fifty while the receiving tube still contains ten millilitres.