Thank you for your questions.
Q#1: About those labels As, Bp, Bs, Cp, Cs, Dp, and Ds. Yes, a 2-letter technical term is to be transcribed in Nemeth. You will use a dot 6 comma since these are not abbreviations.
I would not retain the bold here because the typeform has no meaning other than to catch the attention of the print reader (as far as I can tell. Is there some indication in the text that gives importance to the bold being used?) We are wisely advised to disregard typeform when all instances of the same item are in the same typeform, and/or when the typeform has no technical meaning. Likewise for the bold applied to letters s and p in s = supernatant; p = pellet. The bold is just eye candy here, as far as I can tell. (If you *were to retain boldface for these 2-letter labels, you would treat them as two bold letters, not one bold word.)
To answer your question about indicators, if you were to use the 3-cell Nemeth typeform indicators right next to a code switch indicator, a space is not required between them. The space required before the opening switch does double-duty for the space required before the typeform indicator. Same goes for the terminators.
I want you to know that the upcoming much-anticipated Nemeth Code will have much clearer rules and examples of the use of typeform indicators inside the switches. Likewise, the upcoming much-anticipated Nemeth Code lesson book will reflect the new rules.
Regarding "4,000 x g" etc. OH MY GOODNESS. A little googling brought up the fact that "g" is indeed a unit of measure here (in the context of physics, centrifugal force, and such). It doesn't mean "grams" in this case, but for our purposes just knowing it is a unit of measure helps us know what to do with it. (Space before, ELI needed.) But what about that "x"? We encounter a similar dilemma in "4x6" where the x doesn't really mean "multiply".
On this topic, UEB 3.9.1, Crosses, is interesting to read. Yes, you need to determine the meaning of the "cross" sign. UEB says that if the cross is used to show dimensions or degree of magnification, to use the multiplication sign. Okay, then in Nemeth-with-UEB that is our cue to switch to Nemeth because we don't use the UEB multiplication cross in a Nemeth transcription.
So ... put "4,000 x g" all in Nemeth, spacing only before the unit "g". I notice that the print document is inconsistent with their spacing (not an uncommon thing). As long as you are consistent with your intentional treatment of these items, your reader will not stumble.
Here is the link to the meaning of "g", if you're curious: https://www.researchgate.net/post/What-is-the-difference-between-the-G-and-the-RPM-in-Centrifugae-Machine-Is-it-same-or-what-Does-it-have-any-specific-formula-for-conversion
Regarding "1x Laemmli" and "4x Laemmli" etc., yes, this refers to a concentration of a solution. So you need to apply the same logic to this as mentioned in Q#2. Even though 4x is not "math" here, the cross sign requires a switch to Nemeth.
Yes, I would assume SDS (on the last line) is an abbreviation. Without any context to rely upon, I would use UEB for SDS, using the capitalized word indicator.
When you are doing worksheets, it can be very helpful to obtain a braille copy of the textbook (if available!) or contact the transcriber (if known!) so you can be consistent with what they did.
About Handout-9-Table1.jpg: In the context of a table, you can either put just (x g) in Nemeth and switch to NC after the column separation lines, or you can do the entire table in Nemeth, which I recommend. See attached brf file.