Ch6 Blood Film Evaluation

Coverslip method

• two square glass coverslips

  • drop of blood in center place second coverslip in crosswise fashion

    • allow drop to spread out then pull apart

Feathered edge

too little RBC

Monolayer

• half the RBC touching, not significantly overlapping

Body

too thick

Blood Flim Examination - Scanning

• scan whole slide at low power and look for cell clumping

Examine erythrocytes at low power (10x) and look for…

• erythrocyte density (low = anemia) (high = hemocencentration)

Examine leukocytes at low power (10x) and look for…

• low density (leukopenia)

• high density (leukocytosis)

monolayer is aprox one

10x field in from the feathered edge

What objecitve is leukocyte evaluation best performed with?

40-50x

• can use 100x (birds and reptiles)

40x

dry (no oil)

50x is better but

requires oil immersion

steps to do manual wbc estimate

• 40 or 50x

• count number of cells in 10 microscopic fields

• take the average (total # of cells counter divided by 10)

• multiple this average x objective squared

Differiental count

• count and classify the first 100 leukocytes you find

  • use 100x to evaluate cytoplasm and nucleus of neutrophils for changes

Erythrocyte evaluation

best performed on 100x objective

Platelet evaluation

• best performed on 100x objective

Estimate platelet number calculation

• count platlets from 10 fields

  • multiple average x 15,000 - 20,000