Ashby technique

The Ashby technique is a method for determining the volume and life span of red blood cells in humans, first published by Dr. Winifred Ashby in 1919.

Differential agglutination of the red cells is then used to determine the number of remaining donor cells, allowing the survival rate to be determined.

It does not involve radioisotope technology, and was the first technique to successfully establish the correct red blood cell life span.

The number of remaining nonagglutinated Type O cells as a function of time defines the survival rate of blood cells.

[2] This technique was used extensively during World War II and shortly after but has more recently been replaced by techniques that label one's own blood, due to the dangers of using donor blood.