I wish to extract information from a .ab1 file. Specifically, the amplitude of primary and secondary base call peaks - P1AM.1 and P2AM.1

library(sangerseqR)
x=read.abif(file.choose())
x@data$P1AM.1

gives me output NULL. Any help regarding what I am doing wrong ?

Works for me - perhaps you have an odd ab1 file?

library(sangerseqR)

x=read.abif("1774_H05_LPR17621_IgE_PC_A11_015.ab1")

str(x@data$P1AM.1)

int [1:1059] 71 1271 235 1004 1118 469 1096 1082 484 824 ...