Subject: Proposed at Operation Knothole or next nearest occasion. Small test to establish suitability of a strain to replace LAF. 1 for routine AB and related work. ech cy sy Suggest set-up at one or two stations, anywhere around tue Lg, SO dose or slightly below, mice of a pure strain for orientation eposur @ to find out. whether this strain could replace the LAF, hybrids now in use. R The exposure is to be made by those interested in acute studies as biological dosimetry; survivals can be taken care of by us. The LAY, mice are excellent, but for purposes ef AB exposure esl-stucies are Very ex-ensive and in my @inion are not necessary. In ppemeeont orde. to get LAF, mice, a lerge breeding colony ef two strains (L and A) has to be set up each time to provide hybrids identical in age et time of exposure. The slightest error in hybridization not evident in LDSo teste may be very significant with respect to chronic studies. Tf ac nge occurs in either of the breeding parental strains, the hybrids will be different and the analysis will become cumbersome, LAP, is homosygous, and it no more imitates hybrids as a parental generation of a pure strain. Now we have some unusual rdiation-induced tunara and do not have recipient LAP, mice for their Therefore, we plead to try out a single strain to replace LA By Date: Oo Not Authorized for Public Release aPaiedionianta EJ Authorized far Public Release By: Date: Entered In OpenNet By. Date: OPENNET ENTRY study. futurs; much money and time (personnel) could be saved therett. mice in the There will be no Mffionlty ef having such stock maintained by a commercial breeder for studies at home laboratories. In all probebility a Jackson “emorial strain would be found acceptable. For selection of this strain or. Heston at NeYeH. or Dr. <nell, Jackson Memorial Leboratary, Bar Harbor, could be consulted. Our RF mice should also be considered. The are susceptible not only to lymphoid but also to ayelold leukemias and ovarian, lung, and other tumors, They are very husky and free from Salmonella and other infections. fr. Christenberry finds them very geod for cataract studies. ea eat cu. ~~ Because of the urgency, a' copyte.being Soruarded to Dr. Cronkite to evaluate the feasibility of this plan and soadvil se the planning committer. ‘We2 THIS PAGE ONLY, DEPARTMENT OF ENERGY DECLASSIFICATION REVIEW SINGLE REVIEW AUTHORIZED BY: DETERMINATION (CIRCLE NUMBER(S] | TV. CLASSIFICATION RETAINED A SA Saat 2. CLASSIFICATION CHANGED TO: TS . 3. CONTAINS NO DOE CLASSIFIEO REVIEWER {ADD}: COORDINATE WITH NAME: hd: CLASSIFICATION CANCELLED “CLASSIFIED iNFO BRACKETED pate: If GU 7. OTHER (SPECIFY): Ws *