3

Erythrocyte sedimentation rate: Principle, procedure

Principle

Blood collected into an anticoagulant is placed in a long graduated tube held in a vertical position. The erythrocyte settles to the bottom, leaving a layer of plasma above. The height of the column of plasma after 1 hour indicates the sedimentation rates of the erythrocytes.

Requirements

  • Trisodium citrate 3.8% solution
  1. Dissolve 32g of Trisodium citrate in 1l of distilled water
  2. Keep the solution at 4 celsius
  • Fresh blood/EDTA anticoagulants blood
  • Westergren ESR tubes, internal diameter 2.5mm,graduated from 0 to 200mm
  • ESR racks
  • Rubber bulbs
  • Test tubes
  • Timer

Westergren tube method

  • Pipette 0.4ml of Trisodium citrate solution into a test tube
  • Add 1.6ml of blood into the same tube
  • Draw citrated blood into the Westergren tube(using a rubber bulb)up to the 0 mark
  • Place the tube in the Westergren stand. Making sure that the tube is completely upright
  • Leave on a bench for 1 hour
  • Then note the high of the column of the plasma in mm graduation starting from the 0mm mark at the top of the tube
  • Express the result as mm/1 hour

Reference ranges

  • Men up to 10mm/hour
  • Women up to 15mm/hour
  • Elderly up to 30mm/hour
  • pregnancy – (first half – up to 48mm/hour), (Second half – up to 70mm/hour)

Sources of Errors

  • Using of wrong volume of blood to anticoagulant
  • Clots in the blood
  • Air bubbles in the tube
  • Leaving mounted test tubes in direct sunlight
  • Non-vertical tubes
  • The vibration of the ESR tube
  • Using a tube which is not dry or not clean
  • High temperature
  • Incorrect reading meniscus

Ushan

3 Comments

  1. Does your website have a contact page? I’m having trouble locating it but, I’d like to shoot you an email.
    I’ve got some creative ideas for your blog you
    might be interested in hearing. Either way, great site and I look forward to seeing it
    grow over time.

  2. I every time used to read post in news papers but now as I am
    a user of internet therefore from now I am using net for
    posts, thanks to web.

  3. Hurrah! After all I got a web site from where I be
    capable of in fact take useful facts regarding my study and knowledge.

Leave a Reply

Your email address will not be published.