Poisson Correction (PC) distance

The Poisson correction distance assumes equality of substitution rates among sites and equal amino acid frequencies while correcting for multiple substitutions at the same site.

MEGA provides facilities to compute the following quantities:

Quantity	Description
d: distance	Number of amino acid substitutions per site.
L: No of valid common sites	Number of sites compared.

Formulas used are:

Quantity	Formula	Variance
$image\poissoncdist_d1.gif$	$image\poissoncdist_d2.gif$	$image\poissoncdist_d3.gif$