I made things harder for myself by pencilling in EMBOLUS at 14ac. It did after all have MB (doctor) and US (American), and an embolus is a clump of cells. Three points of agreement seemed compelling! Of course, I couldn’t explain the E - - OL in the answer. And worse … I was, as you can see below, working with an incorrect or incomplete definition.
In fact, on looking through the blog, I think it’s fair to say that this puzzle featured an outstandingly well disguised set of definitions! Look for example at 1, 6, 12, 14, 20 and 26 across, and 3 and 9 down. The definition that utterly delighted when I finally saw the answer was 20ac. Special mention! The uncertainty principle was worth a smile too. I also loved the clever juxtaposition in 10ac. Thanks to the setter.
Clues are in blue, with definitions underlined. Answers are in BOLD CAPS, then wordplay. (ABC*) means 'anagram of ABC'. Deletions are in [square brackets].
1 Male dog is cuddled by computing pro with file? (10)
MANICURIST: MAN, then CUR_IS is “cuddled” by IT.
6 Give a wave to mass retailer on the way back (4)
PERM: M (mass), REP (retailer) all reversed (“on the way back”). A small quibble: the sales reps I’ve encountered have all worked for wholesalers, not retailers. The people talking to the end customers are salespeople to me. Perhaps this a difference in usage between countries?
10 A greeting from abroad, going west? (5)
ALOHA: “hola” is a Spanish greeting. Going right to left (i.e. “west”), A_HOLA becomes ALOHA. And of course, Hawaii, the home of the “aloha”, is a long way west of the UK. Brilliant clue! On edit: by "going right to left" or "going west", I mean written backwards.
11 Intimate a new baby with many siblings is in litter (9)
PALANQUIN: PAL, A, N[ew], QUIN.
12 Ship rocking when in colder harbours or weak swell (8,6)
CHINLESS WONDER: anagram (“rocking”) of (SS WHEN IN COLDER*), where SS is a ship.
14 Medic's injecting bodily fluid in American's cells (7)
MOBILES: BILE (bodily fluid) “injected” into MO’S. The definition refers to cell phones, of course.
15 A measure of acid, when current, leads to a disorder(7)
APHASIA: A, PH (pH is a measure of acidity), AS (when), I (electrical current), A.
17 Turkey's leader confirmed as touchy? (7)
TACTUAL: T[urkey], ACTUAL. I didn’t know the answer, and struggled with whether “confirmed” is “actual”, but I suppose it’s OK. And, “tactual” is of the same form as “visual” and “aural” for example. The one slightly disappointing clue for me.
19 Pasting fancy lace on sack the wrong way (7)
DEBACLE: DEB=BED (sack) the wrong way; ACLE=(LACE*), “fancy”.
20 Scatter articles from Spanish American writer (4,10)
ELLA FITZGERALD: EL and LA are the Spanish articles, FITZGERALD (F. Scott, or Zelda) is the American writer. And, of course, Ella was the supreme scat singer. Delightful definition!
23 Hollow blocks harden and contract (9)
INDENTURE: DENT “blocking” INURE.
24 Signal recalling the marines (5)
ALARM: . à la (“recalling”), RM (Royal Marines).
25 Attic maybe concealing right anorak (4)
GEEK: a Greek concealing the R.
26 Crackpot here begins to give name in uncertainty (10)
HEISENBERG: (“crackpot”) anagram of (HERE BEGINS*). Heisenberg’s Uncertainty Principle is a major concept in quantum physics.
1 Beef — love digging into piece (4)
MOAN: O (love, or zero) in MAN (chess piece, perhaps).
2 Hope no novel writer's appalled by the novel (9)
NEOPHOBIC: “novel” (HOPE NO*), BIC.
3 Water sport for Norman, say, a remote activity (7-7)
CHANNEL-SURFING: whimsical definition (since Normandy is on the English Channel), then a just slightly less whimsical one.
4 Turning some crasser perfume bottle up (7)
REPRESS: reversed hidden answer (“turning some”).
5 Polish area of icon's head in lit up aisles (7)
SILESIA: I (head of icon) in “lit up” (AISLES*).
7 At first, Ezra Pound could be an ass (5)
EQUID: E (Ezra at first), QUID.
8 Awe-inspiring underground worker, one with special powers (4-6)
MIND-READER: MINER (underground worker) “inspiring” DREAD (awe).
9 Where drinkers go and make advances too (4,3,7)
INTO THE BARGAIN: drinkers go INTO THE BAR, then GAIN (make advances).
13 Dash to confess about affair (10)
SMATTERING: SING around MATTER.
16 What harvester has: welcome recovery period (4,5)
SICK LEAVE: a harvester might even today have a SICKLE. AVE was a Latin greeting.
18 Leaves disconnected phone around middle of den (7)
LETTUCE: CUT TEL “around”, then [d]E[n].
19 Stray she-cat, with head covered by diamonds (7)
DIGRESS: [t]IGRESS, with head covered by D.
21 By Hollywood location, delve regularly for scoop (5)
LADLE: Hollywood is in LA, then odd letters of DeLvE.
22 Sticks up for superior (4)
SMUG: GUMS “up”.