It provides eleven buffer standards in the 10^-4 to 10^-8 M Ca₂⁺ range, whereas other commonly used fluorescent Ca₂⁺ indicators have the apparent Kd in the range of 100 to 300 nM. As with any ionic sensitive indicator, the sensitivity range of these indicators is about 1.0 log unit above and below the K_d. CALBUF-2 provides seven calibration points in this sensitivity range. It has an osmolarity of 0.305, which is isotonic with most mammalian cells.
Concentration: 1x10^-8, 4x10^-8, 1x10^-7, 2.5x10^-7, 5x10^-7, 7.5x10^-7, 1x10^-6, 4x10^-6, 1x10 ^-5 , 4x10^-5 , and 1x10-^-4 M at 20°C. Ionic strength: 0.150 M. 11 bottles, 20 ml each. Limited shelf life. Use within 30 days.

A set of eight calcium buffers covering the range of concentration from 10^-1 to 10^-8 M Ca₂⁺. Each buffer contains 20 ml of solution and enough potassium chloride to set the ionic strength to 0.1 M. Limited shelf life. Use within 30 days.