A protein was eluted at 15 ml when passed through a gel filtration column with a void volume of 5 ml and a pore volume of 1 ml. The Kd value of the protein is

The Kd value, or partition coefficient, is a measure of how a protein distributes itself between the mobile phase and stationary phase in chromatography. It can be calculated using the formula:

Kd = (Ve - V0) / (Vt - V0)

where: Ve = elution volume (the volume at which the protein comes off the column) V0 = void volume (the volume at which molecules too large to enter the pores come off the column) Vt = total pore volume (the volume within the beads of the column)

Given in the problem: Ve = 15 ml V0 = 5 ml Vt = 1 ml

Substituting these values into the formula gives:

Kd = (15 ml - 5 ml) / (1 ml - 5 ml) = 10 ml / -4 ml = -2.5

However, this result is not physically meaningful because the total pore volume (Vt) should be larger than the void volume (V0). The pore volume is the volume within the beads of the column, while the void volume is the volume of the column not occupied by the beads. Therefore, there seems to be a mistake in the problem as stated. Please check the values and try again.