text: Yo, listen up, I got a procedure to drop,
  Measuring cortisol and 11-deoxycortisol, non-stop.
  In plasma or serum, it's the way to go,
  Keep the content unchanged, let the knowledge flow.
  
  Half a milliliter of plasma, that's the key,
  Extracted with methylene chloride, you see?
  Separate cortisol and deoxycortisol, no doubt,
  Using Sephadex LH-20 mini-column, gotta shout it out.
  
  Now let's get to the assay, it's the real deal,
  With a cortisol kit, commercial appeal.
  Coated tubes with rabbit anti-cortisol, man,
  They do the trick, stick to the plan.
  
  But hold up, there's a twist, gotta mention,
  This antibody's got some crossreactivity, pay attention.
  20% crossreactivity with 11-deoxycortisol, don't ignore,
  It's a factor you gotta explore.
  
  Now this procedure's got a special use,
  Assessing pituitary-adrenal reserve, no excuse.
  In the Metyrapone test, it's the way to go,
  Rap it out, let the knowledge flow.