Hi

I am trying to use the StringDB package to map protein interactions. As a first step I need to get the species I am mapping which is C. griseus (Chinese hamster). I got the following info from the String website

Name: Cricetulus griseus Aliases: (Chinese hamster / Chinese hamsters / C. griseus / CHO cell lines / Cricetulus aureus / Cricetulus barabensis griseus / Cricetus griseus) STRING-type: periphery distinct protein-coding genes: 21808 NCBI taxon-Id: 10029

and my code is

BiocManager::install("STRINGdb")
library("STRINGdb")

#read in proteins to be mapped
Attached_DE_Proteins <- read.csv("C:/PETER PROJECT/3d. Mass Spec Processing/Results of R Analysis/DE Gene Lists/Effect of Serum/WCL Analysis/0% Attached v 5% Attached/DE Cutoff equal 1.5/DE 1-5 Attached Cells DE Gene IDs WCL Apr19 Serum Removal.csv")

#call the string database. 
#note if you supply a local input directory the DB will be cached here allowing offline use.
string_db <- STRINGdb$new( version="11", species=10029, score_threshold=400, input_directory="")

#map my DE proteins to the String DB
mapped_proteins <- string_bd$map(Attached_DE_Proteins, "HGNC_Symbol", removeUnmappedRows = TRUE)

However, I get the following error when I run it.

Error: object 'string_bd' not found

Any thoughts on where I am going wrong? I'm still a newbie to the bioinformatics field.

Thanks