Hey, good to see you here :-d …… In this article, we’re gonna discuss the Preparation Of Normal Saline Solution….. If you have any queries, don’t forget to mention in comments….. Thanks

Normal Saline Solution (NSS) is commonly used in various laboratory procedures like in the preparation of Red cells Suspension for the crossmatch, for preparing dilutions of Reagents, for stool examinations, to make the dilutions in serological tests, diagnostic tests etc.

There are commercially prepared Normal saline solution available in the market but it can easily be prepared manually in the laboratory whenever required.



The normal saline solution is simply the 0.85% Sodium chloride (NaCl) solution which can be prepared in the laboratory by dissolving the calculated amount of Sodium chloride crystals in the required quantity of Distilled water.

The Normal saline solution is prepared as follows……

Calculation For Normal Saline Solution…..

[wp-svg-icons icon=”point-right” wrap=”i”] A normal saline solution is the 0.85% sodium chloride solution.

[wp-svg-icons icon=”point-right” wrap=”i”] That means 0.85 gm of sodium chloride in 100 ml distilled water.

[wp-svg-icons icon=”point-right” wrap=”i”] For preparing 1 L normal saline solution we require,

W1 / V1 = W2 / V2

W1 = Required quantity of sodium chloride for 100 ml NS = 0.85 gm

V1 = Required volume for 0.85 gm sodium chloride to make NS = 100 ml

W2 = Required Quantity of Sodium chloride to make the desired quantity of Normal Saline solution

V2 = 1000 ml (or desired quantity of Normal saline to be prepared)

0.85 gm / 100 ml = W2 gm / 1000 ml

0.85 gm × 1000 ml = W2 × 100 ml

W2 = 0.85 × 1000 ml / 100 ml

W2 = 8.5 gm

Thus, to prepare 1000 ml of Normal saline solution 8.5 gm sodium chloride crystals should be dissolved in 1000 ml of distilled water.

Apparatus Required…..




  • Weighing scale
  • Volumetric flask/beaker
  • Stirrer
  • Funnel

Chemicals Required…..

  • Distilled water
  • Sodium chloride (NaCl)

Procedure For Normal Saline Solution…..

[wp-svg-icons icon=”point-right” wrap=”i”] Weigh 8.5 gm of Sodium chloride (NaCl) with the help of weighing scale.

[wp-svg-icons icon=”point-right” wrap=”i”] Now take 500 ml of distilled water in the volumetric flask or in a Beaker and to this add 8.5 gm NaCl.

[wp-svg-icons icon=”point-right” wrap=”i”] Swirl the flask gently to mix the contents or stir in case you are making the solution in a beaker with the help of stirrer.

[wp-svg-icons icon=”point-right” wrap=”i”] When NaCl dissolves completely then add distilled water and make the final volume 1 liter.

[wp-svg-icons icon=”point-right” wrap=”i”] Insert an air-tight stopper into the mouth of the volumetric flask and shake it gently to make the solution homogeneous or if you are using a beaker stir the solution well using a stirrer.

[wp-svg-icons icon=”point-right” wrap=”i”] Now Autoclave the prepared normal saline solution at 121 °C, 15 psi pressure for 15 minutes. This will sterilize the solution and made it the Laboratory grade Normal saline solution which can be used in pathological as well as microbiological analysis.

[wp-svg-icons icon=”point-right” wrap=”i”] If you have prepared the Normal saline in a beaker transfer it to the volumetric flask or Erlenmeyer flask and autoclave it at 121 °C, 15 psi pressure for 15 minutes.

In this way the Laboratory grade Normal saline solution is prepared in the laboratories.

Frequently Asked Questions (FAQs)

0.9% saline means that there are 0.9 grams of sodium chloride (NaCl) per 100 mL of solution. Therefore, 100 mL of 0.9% saline contains 0.9 grams of NaCl.

To make 0.9% NaCl (normal saline) 500 mL, you need to dissolve 4.5 grams of NaCl in 500 mL of sterile water.

The number of drops in 1 mL of normal saline depends on the size of the dropper. A standard dropper usually delivers 20 drops per 1 mL.

1 mL of normal saline contains 0.9 grams of NaCl.

To make 1 liter of normal saline, you need to dissolve 9 grams of NaCl in 1 liter of sterile water.

To make 500 mL of normal saline, you need to dissolve 4.5 grams of NaCl in 500 mL of sterile water.