(a) While lawyers are associated in a firm, none of them shall knowingly represent a client when any one of them practicing alone would be prohibited from doing so by rule 4-1.7, 4-1.8(c), 4-1.9, or 4-2.2.

(b) When a lawyer becomes associated with a firm, the firm may not knowingly represent a person in the same or a substantially related matter in which that lawyer, or a firm with which the lawyer was associated, had previously represented a client
whose interests are materially adverse to that person and
about whom the lawyer had acquired information protected by rules 4-1.6 and 4-1.9(b) that is material to the matter.

(c) When a lawyer has terminated an association with a firm, the firm is not prohibited from thereafter representing a person with interests materially adverse to those of a client represented by the formerly associated lawyer unless:

(1) The matter is the same or substantially related to that in which the formerly associated lawyer represented the client; and

(2) Any lawyer remaining in the firm has information protected by rules 4- 1.6 and 4-1.9(b) that is material to that matter.

(a) While lawyers are associated in a firm, none of them shall knowingly represent a client when any one of them practicing alone would be prohibited from doing so by Rules 1.7 or 1.9,

unless the prohibition is based on a personal interest of the prohibited lawyer and does not present a significant risk of materially limiting the representation of the client by the remaining lawyers in the firm.

[ABA MODEL RULE 1.9
(b) A lawyer shall not knowingly represent a person in the same or a substantially related matter in which a firm with which the lawyer formerly was associated had previously represented a client

(1) whose interests are materially adverse to that person; and
(2) about whom the lawyer had acquired information protected by Rules 1.6 and 1.9(c) that is material to the matter; unless the former client gives informed consent, confirmed in writing.]

BACK TO MODEL RULE 1.10
(b) When a lawyer has terminated an association with a firm, the firm is not prohibited from thereafter representing a person with interests materially adverse to those of a client represented by the formerly associated lawyer and not currently represented by the firm, unless:

(1) the matter is the same or substantially related to that in which the formerly associated lawyer represented the client; and

(2) any lawyer remaining in the firm has information protected by Rules 1.6 and 1.9(c) that is material to the matter.