Hemoglobin Determination (Worksheet #4 | P)

Question 1

Hgb is measured as what?

Answer 1

Oxyhgb

Question 2

Some methods measure oxyhgb indirectly by converting it to compounds like what?

Answer 2

1) Acid hematin
2) Cyanmethemoglobin
3) Alkali hgb
4) Carboxyhgb

Question 3

What are the other indirect methods of determining hgb lvls?

Answer 3

By detecting the concentrations of O2 and Fe carried by the hgb molecule as well as by the blood’s SG

Question 4

What are the mats needed for hgb determination?

Answer 4

1) EDTA blood
2) 0.1 N HCl
3) Distilled H2O
4) Suction device / aspirator / sampler
5) Hgbometer
- > Comparator block
- > Sahli’s pipette
- > Sahli’s or square tube
- > Dropper
- > Stirring rod
6) Wassermann tube
7) Drabkin’s rgnt
8) Cyanmethemoglobin std
9) Spectrophotometer

Question 5

What are the 2 main methods of hgb determination?

Answer 5

1) Acid Hematin Method

2) Cyanmethemoglobin (MHbCN) or Hemiglobin Cyanide (HiCN) Method

Question 6

What is the principle in acid hematin method?

Answer 6

1) The principle in this method is the conversion of hgb to acid hematin by using 0.1 N HCl
2) The yellowish solution is compared to the color of the std in the comparator block

Question 7

What is the process of acid hematin method?

Answer 7

1) Deliver 0.1 N HCl up to the 2 mark of the Sahli’s or square tube
2) Aspirate 0.02 mL of blood using Sahli’s pipette or sampler
3) Expel the said volume of blood to the Sahli’s tube containing the 0.1 N HCl
4) Rinse the pipette w/ distilled H2O 3 times, adding all the washings to the mixture of blood and diluted acid. Mix and stand for at least 10 mins
5) Add distilled H2O to the mixture drop by drop, ensuring the thorough mixing after each addition w/ the use of the stirring rod. Continue adding distilled H2O until the solution matches that of the std on the comparator block
6) Take the reading of the lower meniscus
7) Report the hgb lvl in gm% or gm/dL or gm/100mL (CU) and in gm/L (SI)

Question 8

What is the purpose of Drabkin’s rgnt (in MHBbCN method)?

Answer 8

It is used to measure hgb through the cyanmethemoglobin method

Question 9

What are the components of Drabkin’s rgnt?

Answer 9

1) Sodium bicarbonate
2) Potassium cyanide
3) Potassium ferricyanide

Question 10

What is the purpose of ferricyanide (in Drabkin’s rgnt) and what is the action of the product (from the action)?

Answer 10

It converts the Fe in the hgb molecule from the ferrous to ferric state, forming methemoglobin or hemiglobin or ferrihgb. The product then combines w/ potassium cyanide to produce cyanmethemoglobin or hgb cyanide