This question may be very simple and basic, but I just need to confirm that I understand the differences among those terminologies in the RNA-Seq context. Suppose I have a sample called SLR, and it is sequenced on 5 lanes, so I have (among other output files) BAM files like L1_SLR, L2_SLR, L3_SLR, L5_SLR and L7_SLR.bam. Here, the letter "L" denotes "lanes". In a typical RNA-Seq experiment, we should expect that reads from those 5 lanes have little variations, right? I am confused with the term "technical replicates" and the "lanes" here -- they're not the same, right? Also, I think these 5 lanes constitute a single "library", that is, one sample corresponds to one library. Am I right? That confused me because I once saw that each library corresponds to a technical replicate (e.g. mutant condition sample having 3 technical replicates, so it has 3 libraries; wild condition sample having 3 technical replicates, so a total of 6 libraries for the expriment). Thank you so much for your clarifications!
thanks for the comments -- so in my situation, will the 5 lanes represent the 5 technical replicates? I am pretty sure that they come from the same sample, i.e. a sample that was sequenced on 5 different lanes. Also, how about the term "library"?
They way you are describing your experiment, I do not think that the 5 lines are technical replicates. The page JC linked to is spot on. For the 5 lanes to be technical replicates, five separate aliquots "from the same solution" would have been extracted and prepared into a library independently of each other. If, however, a large aliquot was extracted and used to prepare a single library, which was then spread across five lanes, I would not call that a technical replicate.
I actually think your original interpretation of how you understand the terminology is correct, keeping in mind what JC pointed out that one lane can actually contain more than one sample/library through a technique called multiplexing so knowledge of the lane the data was captured from may not tell you much about the nature of the data itself.
"will the 5 lanes represent the 5 technical replicates?" Possibly. "how about the term "library?" Library preparation is the process by which the RNA is fragmented and adapters are added so that it's ready for sequencing.