The protective effects of trehalose on freeze-drying and LAMP reagents storage

With the unique advantages of high sensitivity,equipment independence,and rapid procedure,loop-mediated isothermal amplification(LAMP) has been extensively developed to detecting various pathogens.The substances of enzyme,dNTP,and other complex organic molecules in LAMP mixture are subjected to a variety of chemical changes under room temperature,many of which are quite unacceptable in terms of storage and transportation.In order to solve this problem,we tried to develop a lyophilization technology for the protection of the LAMP mixture with the addition of trehalose as a stabilizer.The predictive effects of freeze-drying and different concentrations of trehalose(5%,10% and 15%) in LAMP mixture during storage under temperature of 4℃,25℃ and 37℃ on amplification activity of LAMP were analyzed systematically.The non-freeze-dried reagents without trehalose were also stored at the same temperature as controls.Our results showed that the lyophilizing LAMP reagents with 15% trehalose exhibited the greatest performance.Furthermore,at 4 ℃,the half-life of freeze-dried mixtures with 15% trehalose(w/v) was 112.3d,which was 6.5-fold of the control.At the temperature of 25 ℃,the half-life of treated reagents was 36.2d,which was 8.7-fold higher than control.Even under the temperature of 37 ℃,the half-life was 6.2d,which was 2-fold of the control.We report here the cost effective,simple developing procedure of a freeze-drying LAMP reagent which will promote the widespread use of LAMP in the field.