text: Yo, check it out, listen up, I got a story to tell,
  'Bout this inhibitory factor that fights Mycobacterial cells.
  It's called MycoIF, yeah, it's real fly,
  Found in mouse spleen cell cultures, don't ask me why.
  
  When stimulated with antigen, it's a sight to behold,
  Inhibited tubercle bacilli from multiplying, that's bold.
  In vitro, in the peritoneal macrophages of mice,
  MycoIF stepped up, put those bacilli on ice.
  
  But hold up, it ain't that easy, let me break it down,
  H37Ra-immunized mice, they needed time to be renowned.
  72 hours of incubation, that's what it takes,
  To produce supernatant fluids with the power to make
  Intracellular inhibition, that's the real deal,
  48 hours won't cut it, it ain't gonna reveal.
  
  Now let's talk culture conditions, gotta get it right,
  At least 1.0% human serum, that's the key, alright?
  In the tissue culture medium, that's the place to be,
  For MycoIF production by the spleen cells, you see.
  
  Freezing, lyophilization, or 60 degrees won't do,
  MycoIF stays strong, it's not affected, it's true.
  But heat it up to 80 degrees, it's a wrap,
  MycoIF gets inactivated, there's no turning back.
  
  Low hydrogen ion concentrations, no worries, it's fine,
  From pH 7 to 12, MycoIF's still gonna shine.
  But drop it down to pH 6 or 5, it's a hit,
  MycoIF's activity decreases, can't deny it, one bit.
  
  pH 4 to 2, oh man, that's the end,
  No more activity, MycoIF won't defend.
  But dilute those supernatant fluids, 1:32, don't you dread,
  They still pack a punch, inhibiting bacilli's spread.
  
  So that's the story of MycoIF, it's a hero in the fight,
  Against Mycobacterial growth, shining bright.
  In the mouse spleen, it's the king of the game,
  Inhibiting those bacilli, earning its fame.