# install.packages("BiocManager")
BiocManager::install("alabaster.string")

library(Biostrings)
example(QualityScaledDNAStringSet, echo=FALSE) # can't be bothered to copy it here.
qdna1
##   A QualityScaledDNAStringSet instance containing:
## 
## DNAStringSet object of length 2:
##     width seq
## [1]     4 TTGA
## [2]     4 CTCN
## 
## PhredQuality object of length 2:
##     width seq
## [1]     4 *+,-
## [2]     4 6789
library(alabaster.string)
tmp <- tempfile()
saveObject(qdna1, tmp)
roundtrip <- readObject(tmp)
class(roundtrip)
## [1] "QualityScaledDNAStringSet"
## attr(,"package")
## [1] "Biostrings"