Assay: Molarity & Dilution

Every result shows its formula and flags the mistakes that quietly cost experiments - protein, oligos, molarity, dilutions, buffers and spins, all on your device.

Assay is a fast, offline bench calculator for scientists - the everyday math of the lab, done right. Unlike a bare calculator, every result shows the formula behind it and warns you about the unit slips and impossible volumes that quietly cost experiments.

WHAT IS INSIDE (free)

• Molarity - mass to concentration, with the un-pipettable-volume guard
• Percent (w/v, v/v) to molarity
• Dilution (C1V1 = C2V2) - impossible dilutions are blocked, not shown as a wrong number
• Resuspension - lyophilised oligo/peptide to a target uM
• ng/uL to nM for DNA and RNA
• Oligo / primer Tm - nearest-neighbour (SantaLucia), GC percent, MW, E260
• Ligation / Gibson - ng, pmol and copies, plus insert-to-vector molar ratios
• Buffer pH - Henderson-Hasselbalch, with a common-buffer pKa picker
• Agarose gel - agarose plus running buffer for any percentage
• RCF and RPM - save your rotors and stop guessing the radius
• Reverse-complement and translate (standard genetic code)
• Protein from sequence - MW, extinction coefficient, A280 and pI, matched exactly to ExPASy ProtParam. Paste a sequence or fetch by UniProt ID.

ASSAY PRO (one-time purchase, no subscription)

• Build and save expressed constructs - tags, linkers and cleavage sites, with the exact MW and E live
• Turn an A280 reading into concentration using its own E
• PCR/qPCR master-mix scaling with overage, template kept separate
• Multi-component buffer preparation from powders and stocks
• Serial-dilution planning - tube count, total diluent and the full range
• Unlimited saved constructs and rotors - reused across every calculator, so their MW and E auto-fill your molarity, A280 and dilutions with no re-keying
• Every future bench tool, included

BUILT TO BE TRUSTED

• Every result prints the formula with your numbers substituted in - one tap to your notebook - plus a plain-English explanation of how it is calculated, with references
• Impossible or ambiguous inputs are caught, never quietly computed
• Protein values matched cell-by-cell to ExPASy; oligo Tm to SantaLucia (1998)

PRIVATE BY DESIGN No account. No ads. No tracking. Your sequences, reagents and saved constructs stay on your device. The only time Assay goes online is when you choose to fetch a public UniProt entry - and even then, only that public ID is sent.

Correctness is never behind the paywall.