To accurately prepare a medication dose with a syringe, you must know how to read the syringe.  The markings on a syringe do not have the same value, it varies with the syringe size or capacity.


Syringes and markings include:  

• Tuberculin (Tb) syringe:  maximum capacity is usually 1 mL although you may have a low-dose Tb syringe with maximum capacity of 0.5 mL.  Markings and numbers reflect hundredths (0.23 mL 0.68 mL, etc) with one mark for each hundredth and numbers every tenth.  This syringe should be used at any time a calculated answer of amount to administer is less than one mL.
   

• Insulin syringe:  is marked in units with one mark for each unit.  Most common capacity is 100 units; however, there are low-dose syringes with maximum capacity of less than 100 units which make it easier to draw up very small doses.  If such a syringe is available, it should be used for small doses (such as less than 10 units).  Insulin syringes should be always be used when administering insulin.
   

• 3 mL syringe markings reflect tenths with a mark for each tenth (1.1 mL; 1.2 mL; 1.3 mL, etc)
   

• 5 mL or 6 mL syringe:  markings reflect tenths; however, there is a mark only for each two tenths (3.2 mL, 3.4 mL, etc).  NOTE:  some manufacturers of syringes make 5 mL and 10 mL syringes whereas other manufacturers make 6 mL and 12 mL syringes.  A given facility will usually only carry one brand.
   

  
  

• 10 mL or 12 mL syringe:  markings reflect tenths; however, there is a mark for only each two tenths (7.2 mL, 7.4 mL, 7.6 mL, etc) 
   

  
  

• 20 mL, 30 mL, 50 mL, and 60 mL syringes:  markings reflect whole numbers or 1 mL increments