Card Set Information
What is the genetic explanation behind Hgb S?
Glutamic Acid is replaced by Valine in position 6 of the beta chain
What does the Sickledex procedure test for?
The presence of Hgb S
Does not indicate amount, or homo/heterozygocity
What is the principle behind the Sickledex test?
Sodium dithionite or sodium hydrosulfite reduces oxygen tension in the soln
Tactoids are formed when the O
environment around the cell is reduced
This causes the characteristic "sickling" of the cells
Hgb S Is insoluble after exposure to soln, and the blood will be opaque
What is the procedure (in detail) for the Sickledex test?
Mix the powdered contents and liquid reagents together
Place 3mL test soln into three test tubes in holder
Fill the pipette w/ capillary action to the black line
Put blood into one test tube, then invert the tube to thoroughly mix
Put the + control into one tube, and mix
Put the - control into the final tube, and mix
Allow to stand
View through solns for result. If blood is opaque then the patient is Hgb S positive