An individual pairwise alignment between CLIBASIA_05175 and its BLASTn find more hits (Additional file 1: Figure S1) shows multiple mismatches on the primer binding regions,

making unlikely a positive amplification with DNA from these other microorganisms. Accordingly, a DNA sample of Candidatus Liberibacter americanus did not produce positive amplification on the LAMP assay targeting CLIBASIA_05175 (Additional file 2: Figure S2). Reactions were optimized to establish the best assay conditions. To determine the optimal temperature, the reaction mixture was incubated at 60, 63 or 65°C for 60 minutes. With all tested temperatures, Las-LAMP products displayed the typical ladder-like pattern on gel electrophoresis with no amplification in the negative control Quisinostat datasheet lacking DNA (Figure 1). However, at 63 or 65°C the reaction was slightly more efficient than at 60°C, with no apparent difference between the first two. The specificity of the amplification was confirmed by sequencing (Additional file 3: Figure S3). As a result of this experiment, the temperature

chosen for the assay was 65°C, as higher temperatures generally produce more stringent conditions for primer binding and greater amplification specificity [25]. We employed a thermal cycler, a water bath or an incubator to maintain the temperature necessary EPZ-6438 for the LAMP assay. The results indicated that all these devices were equally capable of producing efficient amplification (Additional file 4: Figure S4). Interestingly, a recent study shows that LAMP can be carried out using chemically driven heaters, a situation that could allow Las-LAMP

amplifications in electricity-free locations [26]. Figure 1 Las -LAMP reaction optimization. Several temperature, time and primer combinations were applied to Las-LAMP to determine optimal reaction conditions. An aliquot of 10 μl of each Las-LAMP reaction was loaded into a 1.5% agarose gel. After electrophoresis, the gel was stained with ethidium bromide. C-: negative control without Template. M: 1 Kb plus DNA ladder (Invitrogen). Next we evaluated the effect of an improvement to the classic Lepirudin LAMP amplification, described previously [18]. Two additional primers named loop primers were added to the reaction mixture. The role of these oligonucleotides is to accelerate the reaction by providing more starting sites for the LAMP auto-cycling process. As shown in the Figure 1, the reaction containing loop primers and incubated at 65°C for 30 minutes performed as well as the reaction without loop primers and incubated for 60 minutes. Therefore, the optimal reaction conditions that were used in all subsequent experiments consisted of incubation at 65°C for 30 minutes with the inclusion of loop primers to the amplification mix.