diff --git a/R/count.R b/R/count.R
index d0bf15e7..7a0fdb1c 100644
--- a/R/count.R
+++ b/R/count.R
@@ -43,7 +43,7 @@
 #' count_R(septic_patients$amox)
 #' count_IR(septic_patients$amox)
 #'
-#' # Or susceptibile isolates
+#' # Or susceptible isolates
 #' count_S(septic_patients$amox)
 #' count_SI(septic_patients$amox)
 #'
diff --git a/R/data.R b/R/data.R
index 4debcbf1..9c747577 100755
--- a/R/data.R
+++ b/R/data.R
@@ -194,9 +194,9 @@
 #'   \item{\code{ward_clinical}}{logical to determine if ward is a regular clinical ward}
 #'   \item{\code{ward_outpatient}}{logical to determine if ward is an outpatient clinic}
 #'   \item{\code{age}}{age of the patient}
-#'   \item{\code{sex}}{sex of the patient}
+#'   \item{\code{gender}}{gender of the patient}
 #'   \item{\code{patient_id}}{ID of the patient, first 10 characters of an SHA hash containing irretrievable information}
-#'   \item{\code{mo}}{ID of microorganism, see \code{\link{microorganisms}}}
+#'   \item{\code{mo}}{ID of microorganism created with \code{\link{as.mo}}, see also \code{\link{microorganisms}}}
 #'   \item{\code{peni:rifa}}{40 different antibiotics with class \code{rsi} (see \code{\link{as.rsi}}); these column names occur in \code{\link{antibiotics}} data set and can be translated with \code{\link{abname}}}
 #' }
 #' @examples
diff --git a/R/first_isolate.R b/R/first_isolate.R
index 59d91f69..4ef2c7bb 100755
--- a/R/first_isolate.R
+++ b/R/first_isolate.R
@@ -205,10 +205,6 @@ first_isolate <- function(tbl,
       stop('Please check tbl for existance.')
     }
 
-    if (is.na(column)) {
-      column <- NULL
-    }
-
     if (!is.null(column)) {
       if (!(column %in% colnames(tblname))) {
         stop('Column `', column, '` not found.')
diff --git a/R/portion.R b/R/portion.R
index f86defca..b26e764c 100755
--- a/R/portion.R
+++ b/R/portion.R
@@ -52,7 +52,7 @@
 #' @source \strong{M39 Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data, 4th Edition}, 2014, \emph{Clinical and Laboratory Standards Institute (CLSI)}. \url{https://clsi.org/standards/products/microbiology/documents/m39/}.
 #'
 #' Wickham H. \strong{Tidy Data.} The Journal of Statistical Software, vol. 59, 2014. \url{http://vita.had.co.nz/papers/tidy-data.html}
-#' @seealso \code{\link[AMR]{count}_*} to count resistant and susceptibile isolates.
+#' @seealso \code{\link[AMR]{count}_*} to count resistant and susceptible isolates.
 #' @keywords resistance susceptibility rsi_df rsi antibiotics isolate isolates
 #' @return Double or, when \code{as_percent = TRUE}, a character.
 #' @rdname portion
diff --git a/man/count.Rd b/man/count.Rd
index 9137ff6f..501fbfc5 100644
--- a/man/count.Rd
+++ b/man/count.Rd
@@ -66,7 +66,7 @@ These functions are meant to count isolates. Use the \code{\link{portion}_*} fun
 count_R(septic_patients$amox)
 count_IR(septic_patients$amox)
 
-# Or susceptibile isolates
+# Or susceptible isolates
 count_S(septic_patients$amox)
 count_SI(septic_patients$amox)
 
diff --git a/man/portion.Rd b/man/portion.Rd
index 590f9505..72e39288 100644
--- a/man/portion.Rd
+++ b/man/portion.Rd
@@ -155,7 +155,7 @@ my_table \%>\%
 }
 }
 \seealso{
-\code{\link[AMR]{count}_*} to count resistant and susceptibile isolates.
+\code{\link[AMR]{count}_*} to count resistant and susceptible isolates.
 }
 \keyword{antibiotics}
 \keyword{isolate}
diff --git a/man/septic_patients.Rd b/man/septic_patients.Rd
index f6921198..4ed2e50c 100755
--- a/man/septic_patients.Rd
+++ b/man/septic_patients.Rd
@@ -12,9 +12,9 @@
   \item{\code{ward_clinical}}{logical to determine if ward is a regular clinical ward}
   \item{\code{ward_outpatient}}{logical to determine if ward is an outpatient clinic}
   \item{\code{age}}{age of the patient}
-  \item{\code{sex}}{sex of the patient}
+  \item{\code{gender}}{gender of the patient}
   \item{\code{patient_id}}{ID of the patient, first 10 characters of an SHA hash containing irretrievable information}
-  \item{\code{mo}}{ID of microorganism, see \code{\link{microorganisms}}}
+  \item{\code{mo}}{ID of microorganism created with \code{\link{as.mo}}, see also \code{\link{microorganisms}}}
   \item{\code{peni:rifa}}{40 different antibiotics with class \code{rsi} (see \code{\link{as.rsi}}); these column names occur in \code{\link{antibiotics}} data set and can be translated with \code{\link{abname}}}
 }}
 \usage{
diff --git a/tests/testthat/test-first_isolate.R b/tests/testthat/test-first_isolate.R
index f9b2a5a7..b9ed1838 100755
--- a/tests/testthat/test-first_isolate.R
+++ b/tests/testthat/test-first_isolate.R
@@ -17,10 +17,11 @@ test_that("first isolates work", {
     suppressWarnings(
       sum(
         first_isolate(tbl = septic_patients %>% mutate(keyab = key_antibiotics(.)),
-                      col_date = "date",
-                      col_patient_id = "patient_id",
-                      col_mo = "mo",
-                      col_keyantibiotics = "keyab",
+                      # let syntax determine these automatically:
+                      # col_date = "date",
+                      # col_patient_id = "patient_id",
+                      # col_mo = "mo",
+                      # col_keyantibiotics = "keyab",
                       type = "keyantibiotics",
                       info = TRUE),
         na.rm = TRUE)),