The Rh_o Variant‐D^u

Abstract

A simplified test for the Du factor employing a reagent containing 25 per cent serum albumin, the “stick” technic to introduce cells and forceful cen‐trifugation has been given an extensive trial in a routine blood bank operation. A routine preliminary test with anti‐D gave 5,051 negative reactions among 26,753 bloods tested. The Du tube test was then performed on the former with an anti‐CDE reagent in parallel with the indirect antiglobulin test done with anti‐D. All bloods positive by one or both tests were tested further for D antigens by an anti‐D elution technic; they were also tested for Rh‐Hr factors. Among the 126 bloods positive by elution for the Dufactor, 122 and 126 were positive respectively by the antiglobulin and the Du tube tests. The two tests were in agreement on all eight of the type ccDuee bloods found in the study. The Dutube test, as done with anti‐CDE, gave no false negative reactions. It is, thus, concluded that bloods which are negative with this test will be type ccddee and can be labeled “Rh negative tested for Du. Serological factors which might account for sensitivity of the Du tube test's being the equal of the antiglobulin test are considered, as are the probabilities of the existence of D variants so weak that they could not be detected by either test.

BLACKLIGHT AND SHORTWAVE UV SENSITIVITY OF NEUROSPORA CRASSA AS A FUNCTION OF CULTURE AGE

“…From the information available, it is not possible to distinguish among the proposed possible mechanisms by which age enhances sensitivity of Neurosporn to both BL and shortwave UV. Fluffy conidial nuclei were stained by the Pittenger method (Pittenger, 1965) except that a 12min hydrolysis in 1 N HCI preceded the staining procedure. Microscopic examination of conidia confirmed fluffy to be uninucleate.…”

Does Knowledge of D^u Status Serve a Useful Purpose?

“…About 50% of de pressed D should be detectable by the onestage enzyme test and classed as D-positive [3]. However, not all of the remainder -the weakest examples -are detectable by the indirect antiglobulin method; from 4% [4] to as many as 15% [5] …”