Viral titer and MOI transduction

FACS percent-positive titer → virus, protamine and media per well

Run

Two chained calculations, exactly as the spreadsheet chains them: a titer in IU/mL from the FACS percent-positive of a virus titration, then the virus, protamine and media to put in each well for a chosen MOI. Everything is editable. The values it opens with are the spreadsheet’s own, so you can check it agrees before you clear them.

appears on the printed sheet
the sheet’s D2 and A27
what every well is topped up to. The sheet says three different things here — see the flag below
saturation limit. 20–30 is the usual linear range. Blank or 0 turns the check off
your pipetting floor — the spreadsheet does not check this. Blank or 0 turns it off
fold apart from each other. A good titration agrees within about 2×. Blank or 0 turns it off

Step 1 — titer from FACS percent-positive

Titer IU/mL = cells × (% positive / 100) ÷ volume of virus (mL), the sheet’s F30 = (C30*B30/100)/D30. The volume column already has the dilution folded into it — 0.001 mL is 10 µL of a 10⁻¹ dilution, not 10 µL of stock. The dilution column is a label; no formula on the sheet reads it, and neither does this, except to show you the implied plating volume so you can check the two agree.

Dilution % positive Cells assayed Volume of virus mL ≡ plated Titer IU/mL
unticking is visible and reversible; nothing is ever dropped for you

Step 2 — transduction setup per well

Virus µL per well = MOI × target cells ÷ titer × 1000, the sheet’s F5 and G5. Protamine is whatever you put in the protamine column — the sheet uses 100 µL of a 10% protamine solution per well. Media is whatever is left of the well volume.

Construct Lot Titer from Titer IU/mL MOI Target cells Wells Virus µL/well Protamine µL/well Media µL/well Total µL/well

Mixes to make

What the spreadsheet leaves unsettled — read before pipetting from it
What this reproduces, cell by cell