The phrase "activity was quantified using" is correct and usable in written English.
It can be used in contexts where you are describing how a particular activity or measurement was assessed or measured in a study or analysis.
Example: "The effectiveness of the training program was quantified using participant feedback and performance metrics."
Alternatives: "activity was measured using" or "activity was assessed using".
Ocular disease activity was quantified using the number of "flare-ups" of uveitis.
MMP activity was quantified using a laser densitometer and expressed as arbitrary units (au).
The antioxidant activity was quantified using four in vitro tests: DPPH/ABTS scavenging assays and ferric/phosphomolybdenum reducing antioxidant power assays.
All organs were weighed (NewClassic ML, Mettler Toledo, Switzerland), and the activity was quantified using a gamma well counter (Cobra II Auto-Gamma, Perkin-Elmer, Waltham, MA, USA), resulting in the average activity per gram of tissue in mice.
After incubation with the labelled peptides, the cells were washed twice with phosphate buffered saline (PBS), solubilised with 1 mL sodium hydroxide (NaOH) and collected and the activity was quantified using a γ-counter (Packard Cobra II Auto Gamma, PerkinElmer, Switzerland).
Firefly luciferase activity was quantified using the Luciferase Assay System (Promega) on a LB9507 Luminometer (Lumat).
TrkB activity was quantified using the previously described KIRA-ELISA assay [28] with slight modifications.
p38 MAP kinase activity was quantified using an immune complex kinase assay kit according to the manufacturer's protocol (New England Biolabs).
Telomerase activity was quantified using a real-time PCR based quantitative telomerase detection kit according to manufacturer's instructions (Allied Biotech Inc., Ijamsville, MD).
Caspase-3 activity was quantified using Facs Canto (BD Biosciences) and the Caspase-3 Detection Kit (Calbiochem) according to the manufacturer's instruction.
Cells were lysed vol:vol in Nonidet P-40 (NP-40) lysis buffer (142.5 mM KCl, 5 mM MgCl2, 10 mM HEPES [pH 7.2], 1 mM EDTA, 0.25% NP-40, 0.2 mM PMSF, 0.1% aprotinin, 1 µg/ml pepstatin and 1 µg/ml leupeptin) at 4°C for 30 min. The protein concentrations were quantified and the caspase activity was quantified using the fluorogenic substrate Ac-DEVD-AMC as described by the manufacturer.
