Why inactivated serum by heat

Heat activation has also been reported to inactivate other undetermined inhibitors of cell growth in culture. However, the practice is labor-intensive and expensive. The protocol must be followed exactly as too high a temperature or too long a time may destroy some growth factors.

On occasion heat inactivation of serum is used because of previous history in the laboratory or for the convenience of stocking only one kind of serum.

In past years, Coriell used all heat-inactivated serum for its cell cultures to inactivate the complement protein found in newborn calf serum. Remove serum and allow to reach room temperature prior to use.

Serum should never be taken from a frozen or refrigerated state and placed in a water bath to expedite thawing or warming. Such handling compromises the quality of the serum and may cause the bottle to break. Many cell culture products use serum that has been heat inactivated to destroy complement that may lead to cell lysis by antibody binding.

Prepare a water bath large enough to accommodate the number of bottles being treated. If serum was thawed in a refrigerator allow serum to come to room temperature prior to placing in water bath. Fill the water-bath with sufficient water so that the product and control bottles are immersed near the serum level. Place a lead weight on the control bottle and place into the center of the water bath.

Mix the contents of the product bottles using a gentle swirling motion until the product is uniform. Place lead circular weights over the tops of the bottles to keep them upright. Place the bottles in the water-bath. Swirl bottle thoroughly every 10 minutes or if applicable turn on the oscillating shaker unit.

If a shaking water bath is not available, ensure bottles are swirled every 10 minutes during the entire process. After 30 minutes turn off the oscillating shaker and remove the bottles from the water bath. Cool to room temperature and either aliquot or return to the freezer.