Learning about coagulation by reading words is like trying to make friends while dressed as a clown, holding an axe, standing in a a cornfield in the middle of nowhere.  Don’t make things hard for yourself. Draw a picture!

But the coagulation cascade looks long and complicated!

That’s just how it LOOKS…in actuality it’s as easy as 12,11,10,9…observe:

  • Write out the factors from 13 to 1 – backwards. You don’t need to differentiate between a particular factor and its activated form (for example, 10 and 10a) because they all become activated
  • 4 and 6 don’t exist
  • 10 is special so it’s out of order
  • 7 is lucky so it’s below the others
  • 3, 5, 8 are helpful mates (they help along particular steps of the pathway)
  • 13 is unlucky so it’s not related “2” anything
  • The factors IN a straight line are part of the INTRINSIC pathway. The aPTT (which has more letters) monitors this pathway (which has more factors)
  • On the other hand, PT (which has fewer letters) monitors the Extrinsic pathway (which has fewer factors)

Once you’ve got a handle on the above, notice that you can remember various other facts about the coagulation cascade using observations like, “10 is a special number so those factors surrounding it – 2,7,9,10 – need vitamin K” , or “lack of ____ factor will result in ____ disease”. The following diagram helped me learn much of coagulation, in conjunction with the text. However, it’s not enough. Do lots of questions with this diagram in mind. I hope it helps.

32 Responses to Coagulation

  1. Carol says:

    Thank you…I have been trying to memorize this forever. This really helps!

  2. Sandra says:


  3. John says:

    Good resource for coag “Clot or Bleed: A painless guide for people who hate coag” can be bought with “The Complete (But Not Obsessive) Hematopathology Guide” both are great. See

  4. Riley says:

    This is SO helpful! Why didn’t I have this while I was doing my CLS program?! I had such a hard time with coag, and everyone else was like “It’s so easy!” Uhh…not for me! This is SO helpful though!

  5. Zedi says:

    One good tip my lab partner gave me: for PTT, the T’s are still together so that’s the intrinsic. For PT, one of the T’s left when they broke up, so now they’re ex’s (extrinsic).

  6. Bessey says:

    a wal-mart theory will also help you to remember factors that go with PTT: if you can’t sell it for $12 try $11.98 ….PTT: 8, 9, 11, 12
    Common factors: 10:2= 5 and just memorize 1 so common factors are 10, 5, 2, 1

  7. Maria Judy says:

    thanks for the tips 😉

  8. Jord says:

    wow!!gr8 information….excellent coagulation diagram…tanx a lot wordsology……

  9. OH, MY……Thank YOU! This has helped in a big way. 6 weeks until my MLT ASCP BOC and counting.

  10. DNA_EXTRACTOR says:

    alots of very usefull information here in wordsology. you can even learn something on the comments 🙂

  11. K21 says:

    One phrase I still remember from my lab instructor: Ex PT In APTt (ex physical therapist in the apartment) haha! Surely helped me survive the program 🙂

  12. EDZ says:

    (BRAD)- PITT has Hepa and his PET is in couma
    *** letter I in the PITT intrinsic and E in the PET extrinsic
    *** PTT-Heparin and PT-Coumadin
    ************ HAHAHAHAHA*****************

  13. Karla says:

    Wow – this is awesome!

  14. Megan says:

    You can remember which test monitors which anticoagulant by using your fingers. Spell out “Coumadin” or “Warfarin” on your fingers, you have two fingers left over for “PT.” Spell out “heparin” on your fingers and you’ll have three left over for “pTT”!

  15. Ben says:

    Hi! I find your website extremely useful. I have started studying for the ASCPi.
    I graduated in 2010 and I have been working as a biomedical scientist in the UK for 7+ years. The problem is that I have only worked in haematology and transfusion. I am now in the USA and I need to take this test before the end of August. I purchased all of the books stated in your passing strategy and the Labce simulator subscription. I do okay when I take a LabCE test in haematology and blood bank (80% on average) but I did terrible when I tried the microbiology, immunology and chemistry tests. We usually don’t work as generalists overseas and I have never worked in these departments. Furthermore I have forgotten a whole lot in micro and chemistry. I feel overwhelmed as this exam seems insurmountable.

    I have a question regarding coagulation. Do I need to memorize all of the factors names? Like Hageman for Factor XII or labile factor for Factor V?

    Thank you very much!

    • wordsology says:

      I don’t think you need to know anything other than the roman numerals and major disorders for coagulation. If you don’t remember much of micro, try to memorize the charts. It may seem like a lot but remember – it’s just the same few species being broken down repeatedly, based on one test or another. Learn the high yield information and do questions in medialab and in the Harr question book (do them in order, subject by subject.) It is NOT insurmountable so just get that out of your head. You may not see it all in one place, but I’ve been receiving feedback daily for two years now from test takers who felt discouraged and sad but passed the exam – often after memorizing all the micro charts and learning the high yield info. The only qualification I would add is that there is no shortcut, despite what you might hear. You have to put in the work (50-100 questions per day in medialab), but be assured that you WILL pass. Others, feel free to chime in.

      • Ben says:

        Thank you so much. I have been doing LavCE test in haematology and I score 75% in this area but I have nit reviewed the leukocyte malignancies or coagulation yet. I think it is not too bad.

        I am using your recommended materials:

        Harr book and LabCE for questions. I am doing 100 questions per day on average but I am only doing it by selected area so far.

        The Polanski cards for the tables and ranges and the Ciulla Success! book for the theory. I am relying on this book a lot as my class notes are from 8 years and they are all in French anyway as I graduated in Belgium.

        Do you think that the Ciulla book is enough for the theory? I am a bit scared that it might not go in depth enough for the ASCP test level. Can I rely strictly on it for the theory? I love it. I love how it is written though. But there are things that I saw in other textbooks that I would be tempted to to study like all of the glycoproteins and complex in the RBC membrane and their biochemical structure and role or the exact content of all the WBC granulations like the bacterial permeability factor or the elastase and gelatinase. These are just a few examples of things that are not thoroughly detailed in the Ciulla book. Maybe it is just me trying to go too much in depth. I am not sure.

        Thank you for your site. You are amazing!

  16. Ben says:

    I just wanted to give you some update! I took the MLT examination on the first week of September 2017 and I passed. I must say that this website has been a source of motivation for me.
    I used the following review materials:
    Polansky flashcards
    Bottom Line Approach (this one was not recommended on your website but it really helps too)
    Your charts and high yield notes
    LabCE everyday
    The BOC book (I think this is more helpful for MLT’s than for MLS’s)

    Not only I passed but I also scored 999 and I was done with the examination in less than an hour.

    Thank you so much for this amazing website. It really gave me guidance and motivation throughout these few months of reviewing!

  17. Ashley says:

    Hi, is 3 a common factor? I am finding different answers for different sites.

  18. vivian says:

    I wish I knew this website before its realy helpful ,taking myAscpi mls exams next month,

  19. vivian says:

    Any help or recommendation will be highly appreciated

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