diff --git a/doc/TP_experimental_biologists.md b/doc/TP_experimental_biologists.md
index 218b6230f31a3b92fc8e8e99dc06823ab5633d8b..ca1fc3fd596d5a5500ed3e3fd1de17ec8cb269a6 100644
--- a/doc/TP_experimental_biologists.md
+++ b/doc/TP_experimental_biologists.md
@@ -1,12 +1,33 @@
+---
+title: "TP for experimental biologists"
+author: Laurent Modolo [laurent.modolo@ens-lyon.fr](mailto:laurent.modolo@ens-lyon.fr)
+date: 6 Jun 2018
+output:
+  pdf_document:
+    toc: true
+    toc_depth: 3
+    number_sections: true
+    highlight: tango
+    latex_engine: xelatex
+---
+
 # TP for experimental biologists
 
 The Goal of this practical is to learn how to build your own pipeline with nextflow and using the tools already *wrapped* in Docker and SGE.
+For this we are going to build a small RNASeq analysis pipeline that should run the following steps:
+
+- remove Illumina adaptors
+- trim reads by quality
+- build the index of a reference genome
+- estimate the number of RNA fragments mapping to the transcript of this genome
 
 ## Initialize your own project
 
 You are going to build a pipeline for you or your team. So the first step is to create your own project.
 
-Instead of reinventing the weel, you can use the [pipelines/nextflow](https://gitlab.biologie.ens-lyon.fr/pipelines/nextflow) as a template.
+Instead of reinventing the wheel, you can use the [pipelines/nextflow](https://gitlab.biologie.ens-lyon.fr/pipelines/nextflow) as a template.
 To easily do so, go to the [pipelines/nextflow](https://gitlab.biologie.ens-lyon.fr/pipelines/nextflow) repository and click on the [**fork**](https://gitlab.biologie.ens-lyon.fr/pipelines/nextflow/forks/new) button.
 
-In git, the action of forking means that you are going to make your own private copy of a repository.
\ No newline at end of file
+In git, the [action of forking](https://git-scm.com/book/en/v2/GitHub-Contributing-to-a-Project) means that you are going to make your own private copy of a repository. You can then write modifications in your project, and if they are of interest for the source repository (here [pipelines/nextflow](https://gitlab.biologie.ens-lyon.fr/pipelines/nextflow)) create a merge request. Merge request are send to the source repository to ask the maintainers to integrate modifications.
+
+