Hb
S – Screening Tests - I
Screening
tests for Hb S
Rubber band method
A rubber band is
wrapped around a finger and left until skin turns blue. Then finger is pricked with a lancet
and a drop of blood examined for sickled cells (holly cells).
Sodium metabisulfite method
A drop of whole blood
(EDTA or heparin) is mixed with sodium metabisulfite and after incubation a slide is
made and examined for sickled cells (holly cells).
This method can not
differentiate between trait and disease forms of Hb S
If test is positive it
should be confirmed using hemoglobin electrophoresis.