# Lab calculators

> The everyday bench maths, with the formula shown: molarity, dilutions and serial dilutions, centrifuge speed, cell counts and seeding, DNA, RNA and protein…

Source: https://khushisingh.in/tools/lab-calculators/
Author: Khushi Singh (khushisingh.in). Licence: CC BY 4.0 for text and original illustrations, unless a credit says otherwise.
Evidence labels used on this site: established, strong evidence, emerging, hypothesis, debated. Where a page has Simple, Curious and Expert versions, all three follow.

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Tools

The everyday bench maths, with the formula shown: molarity, dilutions and serial dilutions, centrifuge speed, cell counts and seeding, DNA, RNA and protein concentrations.

*[Here the web page has an interactive activity; open the source URL to use it.]*

## Check before you pipette

The calculators do arithmetic; they cannot know your reagents. Use the formula weight on the bottle, the radius from your rotor’s manual and the ε of your own protein, and have someone check a new recipe. Nothing you type is sent or stored.

## References

1. Green MR, Sambrook J. 2012. Molecular Cloning: A Laboratory Manual, 4th edition. Cold Spring Harbor Laboratory Press. (A260 conversion factors.)
2. Pace CN, Vajdos F, Fee L, Grimsley G, Gray T. 1995. How to measure and predict the molar absorption coefficient of a protein. Protein Science 4:2411–2423. [doi:10.1002/pro.5560041120](https://doi.org/10.1002/pro.5560041120)
3. Strober W. 2015. Trypan blue exclusion test of cell viability. Current Protocols in Immunology 111:A3.B.1–A3.B.3. [doi:10.1002/0471142735.ima03bs111](https://doi.org/10.1002/0471142735.ima03bs111)