The phrase "adding the same volume" is correct and usable in written English.
It can be used in contexts where you are discussing the process of including an equal amount of a substance or material in a mixture or calculation.
Example: "When preparing the solution, make sure to follow the recipe by adding the same volume of water as the amount of sugar."
Alternatives: "including an equal volume" or "incorporating the same amount".
The enzymatic reaction was stopped by adding the same volume of MSC media to cells.
Proteins and polymers were precipitated by adding the same volume of acetonitrile to the plasma fraction.
Metastable solutions (500 ml volume) at Ω = 9.4 ± 0.5 were first introduced into a temperature-controlled (water-jacketed) stirred (at 150 RPM) 1 liter reactor by adding the same volume of separate chilled solutions of CaCl2 and NaHCO3.
The chromogenic reaction was stopped by adding the same volume of 0.5 M H2SO4.
For SDS-PAGE, yeast cells were harvested at mid-log growth, washed, and after adding the same volume of glass beads, were extracted with lysis buffer (50 mM Tris/HCl, pH 8.0, 2 mM PMSF supplemented with protease inhibitors).
After adding the same volume of phenol∶chloroform ∶isoamyl alcohol (25∶24∶1) pH 8.0, samples were mixed, incubation at 65°C for 15 min and centrifuged at 10,000 g for 15 min (for plates: 3,200 g for 30 min).
Measure the resulting juice and add the same volume of sugar (plus 1 tsp of lemon juice for every cup of juice) and bring to the boil, then set aside to cool.
Dry the gel pieces in a vacuum centrifuge for 5 min. Swell the gel pieces with the digestion buffer (100 mM NH4HCO3, 5 mM CaCl2 and 150 ng trypsin per 2-100 ng protein spot) on ice for 45 min. Add the same volume of the digestion buffer, but without trypsin, to keep the gel pieces wet during the digestion period (25°C, overnight).
Equal volumes of buffer were added to the same volume of GdnHCl solutions and these mixtures were used as blank.
From the third day, the trials ASSwS and nASSwS were weekly added with 300 mL of S. maltophilia LMG 6606 cell suspension (concentration at about 108 CFU mL−1), while the trials ASwR and nASwR were added with the same volume of Ringer's solution.
After 1 minute of incubation, the stools suspension was filtered through a metalic mesh and a volume of sulfuric ether was added to the same volume of filtered material in a centrifuge tube, and then emulsified by vigorous agitation.
