Cell dilution calculator

Invalid inputs fail with invalid_input and are not billed.

What cell-suspension dilution means at the bench

A target denser than the stock is not a dilution at all; you would need centrifugation, a filter, or a richer culture, so this endpoint fails with invalid_input instead of returning a negative diluent.

Input contract, response fields, and validation

Desired concentration must not exceed initial concentration. Missing fields, non-positive densities or volume, and a target above the stock are not billed. POST a JSON body with three required finite positive numbers: initial_concentration as the stock cell density C1 (aliases c1, stock_concentration, cell_concentration, stock, initial), desired_concentration as the target density C2 in the same unit (aliases c2, target_concentration, final_concentration, desired, target), and final_volume as the filled volume V2 (aliases v2, volume, target_volume, v_final). Concentrations and volume may arrive as JSON numbers or numeric strings; booleans, empty strings, and non-finite values fail with invalid_input naming the field. Example: initial_concentration two million four hundred thousand, desired_concentration five hundred thousand, final_volume ten returns sample_volume two point zero eight three repeating, diluent_volume seven point nine one six repeating, and dilution_factor four point eight. A tenfold drop from one million to one hundred thousand cells per milliliter in ten milliliters returns sample_volume one and diluent_volume nine with dilution_factor ten. On success the response echoes the three inputs with stable twelve-decimal rounding, plus sample_volume as the stock aliquot to pipette, diluent_volume as the medium or buffer to add, dilution_factor as C1 over C2, formula restating the two volume identities, and a short English message. Successful work is priced at a flat $0.002 with unit item.

Workflows, units, pricing, and related search intent

Teaching labs can fix a textbook count so students practice the rearrangement without arithmetic slips. Keep units aligned yourself: if density is cells per milliliter, volume is milliliters; if you work in microliters, use cells per microliter or convert first—the engine never converts milliliters to microliters. This is not a chemical molarity dilution solver, not a serial-dilution chain, and not an OD600-to-CFU converter, though those tools often sit next to cell-suspension prep in the same session. Search phrases that belong here include cell dilution calculator, dilute cell suspension to target concentration, how much medium to add after a cell count, and sample volume for seeding density. Typical workflow: count the stock, choose a seeding density and a flask or well volume, send the three numbers, pipette sample_volume of cells, and bring to volume with diluent_volume of medium. Plate-seeding scripts can call the API after each count so six-well, twenty-four-well, and T-seventy-five recipes stay consistent without a spreadsheet hidden in every notebook. Failed validation does not consume prepaid balance, so exploratory scripts that probe an over-dense target stay cheap. Round-trip checks are straightforward: confirm sample plus diluent equals final volume after published rounding, confirm sample times initial equals desired times final within rounding, and confirm that raising desired above initial flips the response from success to invalid_input.